Green Routes for Synthesis of Zeolites - Chemical Reviews (ACS

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Green Routes for Synthesis of Zeolites Xiangju Meng and Feng-Shou Xiao* Department of Chemistry, Zhejiang University (XiXi Campus), Hangzhou 310028, China 5.3.1. Ionothermal Synthesis of Zeolites Assisted by Microwave Radiation 5.3.2. Microwave-Enhanced Ionothermal Synthesis of Zeolite Membranes 6. Summary and Perspectives Author Information Corresponding Author Notes Biographies Acknowledgments References

CONTENTS 1. Introduction: Zeolites and Green Chemistry 2. Green Routes for Use of Organic Templates in Zeolite Synthesis 2.1. Organic Templates in Zeolite Synthesis 2.2. Synthesis of Zeolites with Low-Toxicity and Cheap Organic Templates 2.3. Synthesis of Zeolites with Recyclable Organic Templates 2.4. Organotemplate-Free Routes for Synthesizing Zeolites 2.4.1. Adjusting Molar Ratios of Starting Gels 2.4.2. Zeolite Seed Solution-Assisted Approach 2.4.3. Zeolite Crystal Seed-Directed Approach 3. Synthesis of Zeolites under Relatively Low Pressure: Use of Ionic Liquids as Solvents 3.1. Ionic Liquids 3.2. Ionothermal Synthesis of Aluminophosphate Zeolites 3.3. Ionothermal Synthesis of Silica-Based Zeolites 4. Solvent-free Synthesis of Zeolites 4.1. Solvent-free Synthesis 4.2. Solvent-free Synthesis of Aluminosilicate Zeolites 4.3. Solvent-free Synthesis of Aluminophosphate-based Zeolites 5. Synthesis of Zeolites with Relatively High Efficiency: Use of Microwave Radiation 5.1. Microwave-Assisted Synthesis 5.2. Microwave-Assisted Hydrothermal Synthesis of Zeolites 5.2.1. Hydrothermal Synthesis of Zeolites Assisted by Microwave Radiation 5.2.2. Microwave-Assisted Crystallization of Zeolite Crystals with Preferred Orientation 5.2.3. Microwave-Assisted Hydrothermal Synthesis of Zeolite Membranes 5.3. Microwave-Enhanced Ionothermal Synthesis of Zeolites © 2013 American Chemical Society

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1. INTRODUCTION: ZEOLITES AND GREEN CHEMISTRY Zeolite crystals with intricate micropores, strong acidity, and redox sites have been widely used as heterogeneous catalysts in the petrochemical and fine chemical industries.1−4 For example, Y zeolites are widely used as solid acid catalysts in refining processes and petrochemistry.1 The applications of TS-1 zeolites in phenol hydroxylation and olefin epoxidation are regarded as milestones in green oxidation.5−7 Notably, most zeolites are usually synthesized under hydrothermal conditions from silicate or aluminosilicate gels in alkaline media at temperatures between about 60 and 200 °C.4,8 The main discoveries and advances in thinking in the field of zeolite synthesis, especially in hydrothermal synthesis from the 1940s up to the present, have been carefully discussed by classical books and several recent extensive reviews.4,8−13 However, the hydrothermal synthesis of zeolites is not a green process (that is, based on the concept of green chemistry) due to the following: Organic templates. Modern synthetic methodologies for synthesizing zeolites typically involve the use of organic molecules that direct the assembly pathway and ultimately fill the pore space.8 Removal of these templates normally requires high-temperature combustion that destroys these high-cost components, producing hazardous (NOx) as well as greenhouse gases (CO2). The associated energy released, in combination with the formed water, can be extremely detrimental to the inorganic structure of zeolites.14 High pressure. Conventional hydrothermal synthesis of zeolites involves heating the reaction mixture (80−200 °C) in a poly(tetrafluoroethylene)- (PTFE-) lined steel autoclave at high autogenous pressure of solvent (mainly water) for a period of time.8 The safety of the equipment is always of concern due to this high autogenous pressure. Low efficiency. The hydrothermal synthesis of zeolites sometimes takes long times (1−20 days) even at relatively high

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Received: March 7, 2013 Published: November 4, 2013

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dx.doi.org/10.1021/cr4001513 | Chem. Rev. 2014, 114, 1521−1543

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Figure 1. Mechanism of Cu-TEPA-templated Cu-SSZ-13 zeolite synthesis. Reprinted with permission from ref 64. Copyright 2011 Royal Society of Chemistry.

temperature (80−200 °C),8 which is considered a high energy cost process. The “green chemistry” concept was introduced in the scientific community in the early 1990s and entails that chemicals and chemical processes be designed to reduce or eliminate negative environmental impacts, involving reduction of waste and improvement of efficiency.15−18 Green chemistry encompasses several major research areas: (1) use of alternative synthetic pathways (e.g., natural processes such as photochemistry and renewable biomass); (2) alternative reaction conditions (e.g., use of solvents with a reduced impact on human health) or increased selectivity and reduced wastes and emissions; and (3) design of ecocompatible chemicals with lower toxicity than current alternatives. To overcome the above disadvantages of conventional zeolite preparation processes, alternative routes for synthesizing zeolites in a green or sustainable manner have been sought. Recently, important advances have been made in the synthesis of zeolites,19 and some typical examples are described below: (a) Zeolite synthesis by use of recyclable, low-cost, or degradable templates: Davis and co-workers14,21−25 have attempted to recycle organic templates in the syntheses of zeolites, while Xiao and co-workers20 have synthesized AlPO zeolites using cheap and degradable guanidine as templates. (b) Organotemplate-free zeolite synthesis: Several groups have sought to synthesize a series of zeolites in the absence of organic templates.26−38 (c) Ionothermal zeolite synthesis: Morris and co-workers39−50 have successfully prepared zeolites using ionic liquids as solvent, eliminating safety concerns associated with high pressure. (d) Solvent-free zeolite synthesis: Ren et al.51 reported a solvent-free route for synthesizing zeolites starting from solid raw materials. (e) Microwave zeolite synthesis: The use of microwave heating results in energy and time savings during synthesis. Moreover, by combining the advantages of ionic liquids and microwave heating, a novel synthesis of zeolites was successfully demonstrated by Tian and Yan and co-workers.52−55 These examples show the potential for zeolite synthesis via green routes. When the enormous amount of zeolite products used globally is considered, green routes for synthesizing zeolites are of great importance. In this review, a brief survey is given of recent developments in the green synthesis of zeolites.

followed shortly after in 196758 with the disclosure of the first high-silica zeolite, zeolite Beta (10 < Si/Al < 100), made with the tetraethylammonium cation as template. Since that time, more than 200 types of zeolites have been prepared in the laboratory in the presence of organic templates. There is no doubt that modern synthetic methodologies for preparing zeolites are based on the wide applications of organic templates.4 However, the use of organic templates bring about some disadvantages, mainly those listed below: Toxicity. The most common organic templates are quaternary ammonium or amines, which are usually toxic and not environmentally benign. Removal of templates. Generally, organic templates are removed by calcination at high temperature to obtain the open pores characteristic of zeolites. The combustion step is always accompanied by the release of hazardous gases (mainly NOx and CO2), high energy consumption, and some amount of structural destruction of the zeolites. Cost. Most organic templates are costly, and calcinations for removing organic templates would result in increased cost for production of zeolites. Thus, new green routes such as using low-toxicity organic templates and recycling the organic templates, as well as organotemplate-free synthesis, is significantly important for the production of zeolites on a large scale in industry.19 2.2. Synthesis of Zeolites with Low-Toxicity and Cheap Organic Templates

Generally, the synthesis of high-silica zeolites requires the presence of organic templates, which are toxic and expensive. Zones and Hwang59 have developed a new approach for the preparation of zeolites using multiorganic amines instead of expensive organic templates. As a typical example, the zeolite structure of MWW is usually templated from hexamethylenimine in aluminosilicate gels. However, Zones and Hwang used a cheap isobutylamine together with a small amount of aminoadamantane to template SSZ-25 (MWW). This route offers economic benefits by reducing the cost associated with structure-directing agents (SDAs) and waste stream cleanup costs, as well as time in the reactor. Furthermore, a series of zeolites such as SSZ-13 (CHA), SSZ-33 (CON), SSZ-35 (STF), and SSZ-42 (IFR) have also been prepared in the same manner by the same group.60 It has been reported that EMT zeolites exhibit much better catalytic properties than Y zeolites, the most important components in fluid catalytic cracking (FCC) catalysts.1,2 However, the industrial applications are significantly limited by use of the costly and toxic template 18-crown-6 in the synthesis of EMT zeolites.61,62 Recently, polyquaternium-6, a component of shampoo, was successfully used as a template to synthesize EMT-rich faujasite.63 As shown by its extensive use in daily human life, polyquaternium-6 is nontoxic and inexpensive. The

2. GREEN ROUTES FOR USE OF ORGANIC TEMPLATES IN ZEOLITE SYNTHESIS 2.1. Organic Templates in Zeolite Synthesis

In 1961, two groups of researchers disclosed their observation of the effect of introducing quaternary ammonium cations into zeolite synthesis, opening a door to the synthesis of novel zeolites in the presence of organic templates.4,56,57 The key step 1522


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Figure 2. (A, top) Dependence of AlPO-5 crystallinity on crystallization time (arrow indicates a large change in crystallinity). (Inset) Structures of tetramethylguanidine and triethylamine. (B, lower left) Nitrogen isotherms and (C, lower right) pore size distribution from adsorption branch for calcined aluminophosphate spheres synthesized at 5 and 6 h in the presence of the organic template tetramethylguanidine. Reprinted with permission from ref 20. Copyright 2009 Elsevier.

ZJM-1; Figure 1), which showed superior catalytic activity in NH3 selective catalytic reduction (SCR) reactions.64 Scientists at UOP have developed the charge density mismatch (CDM) approach to prepare zeolites via addition of alkali and alkaline earth cations at low levels, which cooperate with organic templates.65−67 Such cooperation allows the use of commercially available organic templates for the discovery of new materials. For example, hexagonal 12-ring zeolites UZM-4 (BPH) and UZM-22 (MEI) were prepared by use of a choline−Li−Sr template system based on the CDM approach.67 Notably, the CDM approach to zeolite synthesis was initially proposed as a cheaper alternative to the trend of using ever more complicated quaternary ammonium species. Recently, the CDM approach has proven to be an efficient tool

successful synthesis of EMT-rich faujasites offers the possibility of industrial applications of EMT zeolites. Due to the urgent need for selective catalytic reduction of NOx by ammonia, industrial applications of Cu-SSZ-13 catalysts are strongly influenced by the need for expensive templates in the synthesis of SSZ-13 zeolites. To obtain less expensive templates, Ren et al.64 have theoretically compared the configuration of the CHA cage, a building unit of SSZ-13 zeolites, with a series of inexpensive inorganic or organic compounds. They found that a low-cost copper complex (Cu2+ coordinated with tetraethylenepentamine, Cu-TEPA) matches the CHA cage well. The copper complex was then successfully used to synthesize the zeolite Cu-SSZ-13 (designated as Cu1523


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Table 1. Synthetic and Physical Parameters of Samplesa sample

SDAb

Si/Xc

% extractedd

CIT-6 Si-Beta-F Al-Beta-F B-Beta-F Si-Beta-OH Al-Beta-OH B-Beta-OH Si-Beta-OH-meso Si-Beta-F-meso Si-MFI-OH Si-MFI-F

TEAOH TEAF TEAF TEAF bis-PIP TEAOH TEAOH/DABCO TEAOH TEAF TPABr HMDA/HF

33.3, 22.1, >500

>99 >99 49 85 h 45 75 >99 >99 h 98

20.0, 18.2, 18 40.0, 29.2, 74 NDi ND, 15.6, ND

porositye (cm3 of liquid N2/g of SiO2 0.233 0.239 0.085 0.222 h ND 0.099 0.248 0.193 h 0.136

(0.237) (0.237) (0.233) (0.241)

(0.250) (0.242) (0.204) (0.146)

TGAf (°C)

% loss B >Al. Additionally, it was shown that these tightly bound organic templates were removed by extraction under conditions that simultaneously hydrolyze part of the framework. For example, TEA+ cations charge-balancing boron atoms in the silicate framework were removed with concomitant hydrolysis of the B−O−Si bonds, releasing the tightly bound TEA+ cations with subsequent desorption of the boron and TEA+ cations from the molecular sieve pores. This method had also been utilized in pure-silica molecular sieves with MFI topology (Table 1). The authors concluded that the amount of organic templates that could be removed by extraction was found to be dependent on the size of organic templates and the strength of interaction of organic templates with the molecular sieve framework.25 Furthermore, they showed a complete recycling of the organic template in the synthesis of ZSM-5.14 They chose a cyclic ketal as an organic template that would remain intact under zeolite synthesis conditions (high pH) and be cleavable at conditions that would not destroy the assembled zeolite (Figure 3). The 13C cross-polarization (CP) MAS NMR

Figure 4. 13C CP MAS NMR spectra: (a) intact 1 inside assynthesized ZSM-5; (b) after cleavage of 1 inside ZSM-5 pores by use of 1 M HCl solution; and (c) after ion exchange with 0.01 M NaOH and 1 M NaCl solution. Reprinted with permission from ref 14. Copyright 2003 Nature Publishing Group.

conditions for assembly of the zeolite and yet can be reversed inside the microporous void space. The fragments formed from the organic template in the zeolite can then be removed from the inorganic framework and be recombined for reuse. Other zeolites such as ZSM-11 and ZSM-12 can also be synthesized in the same manner, suggesting that the route can be used as a general methodology in the field of zeolite preparation.72 2.4. Organotemplate-Free Routes for Synthesizing Zeolites

An alternative route for solving the problems caused by organic templates is to avoid their use entirely. Several methods including adjusting molar ratios of the starting gels26,73−81 or the addition of zeolite seed solutions27,29,31 or zeolite crystal seeds28,30,32,33,35−38,82−85 into the starting gels, have been reported for synthesis of aluminosilicate zeolites in the absence of organic templates.86 The zeolite seed solutions referred to here are zeolite precursor solutions or solutions containing the primary and secondary building units of zeolites, while the term “zeolite seeds” refers to solid zeolite crystals remaining in the synthesis system. 2.4.1. Adjusting Molar Ratios of Starting Gels. The synthesis of ZSM-5 zeolites in the presence of tetrapropylammonium (TPA) can be regarded as a milestone in the history of hydrothermal zeolite synthesis.87 Following the discovery of ZSM-5, there developed a belief that this zeolite could only be made by use of a suitable organic template (usually TPA+) or through the addition of existing ZSM-5 seeds.4,87 Grose and Flanigen73−75 prepared well-crystallized ZSM-5 from the Na2O−SiO2−Al2O3−H2O system, which is the first example of an organotemplate-free synthesis of ZSM-5. Around the same time, another two groups reported that ZSM5 with good crystallinity can be successfully synthesized in the absence of any organic templates.76,77 Later, Shiralkar and Clearfield78 reported that the Si/Al and Na/Al ratios are key factors for the organotemplate-free synthesis of ZSM-5 zeolites. The composition of the starting gel was aSiO2:Al2O3:bNa2O:1500H2O. When a is less than 30, the products were composed of mordenite as the major phase

Figure 3. Schematic representation of the synthetic methodology for preparation of ZSM-5 using 1 as template. Step 1, assemble the SDA with silica precursor, H2O, alkali metal ions, etc., for zeolite synthesis. Step 2, cleave the organic molecules inside the zeolite pores. Step 3, remove the fragments. Step 4, recombine the fragments into the original SDA molecule. Reprinted with permission from ref 14. Copyright 2003 Nature Publishing Group.

spectrum showed that the as-synthesized material contains intact 8,8-dimethyl-1,4-dioxa-8-azaspiro[4,5]decane (1, Figure 4a). When the ZSM-5 was treated with 1 M HCl solution at 80 °C for 20 h, the 13C CP MAS NMR spectrum obtained was consistent with the presence of the ketone fragment (Figure 4b), suggesting that 1 could be cleaved into the desired pieces inside the zeolite pore space. After ion-exchange treatment with a mixture of 0.01 M NaOH and 1 M NaCl at 100 °C for 72 h, 1,1-dimethyl-4-oxopiperidinium (2) could be completely removed as shown in the 13C CP MAS NMR spectrum (Figure 4c). Conceptually, this strategy involves assembly of an organic template from at least two components, using covalent bonds and/or noncovalent interactions that are able to survive the 1525


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along with traces of ZSM-5. However, when a is above 60, the contribution from α-quartz increases, coexisting with ZSM-5 and mordenite. Almost 100% pure α-quartz was obtained when the gel used was free of alumina. Increasing the value of b also resulted in the formation mordenite or α-quartz as impure phase. At a starting composition of a = 40 and b = 4.5−6.0, pure ZSM-5 with the occlusion of Na+ in excess of charge compensation on the zeolite framework can be well crystallized. Notably, the thermal stability of such ZSM-5 synthesized in the absence of organic templates was less than that of conventional ZSM-5, due to occluded excess sodium species.78 The organotemplate-free synthesis of ECR-1 zeolite is also a successful example of adjusting the molar ratios of starting gels.26ECR-1, a large-pore aluminosilicate zeolite, is an intimate twin of the mordenite-like sheets between layers of mazzite-like cages, which was first discovered by use of the organic template bis(2-hydroxyethyl)dimethylammonium chloride.88−90 Later, other organic templates such as adamantine-containing diquaternary alkylammonium iodides and tetramethylammonium (TMA+) were also used in synthesis of ECR-1.91,92 In these cases, organic templates are necessary in the synthesis of ECR-1. However, gallosilicate zeolite (TNU-7), an analogue of aluminosilicate ECR-1, is hydrothermally synthesized in the absence of organic templates, a process attributed to the structure-direction effect of inorganic Ga3+ species.79 The success of TNU-7 suggested that ECR-1 might be prepared in the absence of organic templates. Song et al.26 synthesized aluminosilicate zeolite of ECR-1 under hydrothermal conditions at 100−160 °C for 1−14 days by carefully adjusting the molar ratios of Na2O/SiO2 in the absence of organic templates for the first time (Figure 5). The

in the synthesis. For example, when the temperature in the synthesis was 160 °C, ECR-1 with an impurity crystallized over 24 h. In contrast, crystallization of ECR-1 at 100 °C took 14 days. Notably, although the synthesis at 100 °C took longer, it was a pure phase of ECR-1. Like the gallium in TNU-7, hydrated alkali-metal cations in the synthesis may organize ECR-1 structural subunits and effect solution-mediated crystallization of the amorphous gel.26 Recently, Zhang et al.80 reported the organic template-free synthesis of ZSM-5/ZSM-11 zeolite intergrowth with different SiO2/Al2O3 ratios, ZSM-5 percentages, and various morphologies by adjusting compositions of the starting gels. It was found that this organic template-free system is well-suited to the synthesis of aluminum-rich zeolites. As the initial Si/Al ratios increase, the crystal sizes and ZSM-5 percentage increase, and the product morphology changes from nanorod aggregate to microspindle and then to single and twinned hexagonal crystals. Moreover, increasing the concentration of Na+ and OH− in the initial reaction gel enhanced the crystallization rate remarkably by shortening the induction period, and the length/ width ratios of the product decreased. Notably, the addition of K+ disfavors the organotemplate-free synthesis of the ZSM-5/ ZSM-11 zeolite intergrowth. More recently, Ng et al.81 reported organotemplate-free synthesis of ultrasmall hexagonal EMT zeolite nanocrystals (6− 15 nm in size) at very low temperature from sodium-rich precursor suspensions. Normally, compared with FAU zeolites as FCC catalysts, EMT zeolites show interesting catalytic properties, but their very high cost currently precludes their practical application. The synthesis of pure EMT-type zeolites usually involves the use of expensive and toxic 18-crown-6 as template.61,62 The novel organotemplate-free synthesis of EMT zeolites offers a good opportunity to develop new FCC catalysts in the future. Ng et al.81 point out that the gel composition, nucleation temperature and times, and type of heating strongly influence the synthesis of EMT zeolites. When the crystallization time is longer or the temperature is higher, the nanoscale EMT materials could be converted into the wellknown FAU and SOD structures. This phenomenon is interpreted by noting that the EMT is the first kinetic, metastable product in this synthesis, followed by conversion into the more stable cubic FAU and more dense SOD structures, which is strongly supported by several studies on EMT/FAU intergrowths.93−95 It is worth emphasizing that the EMT synthesized from the organotemplate-free route still has relatively low Si/Al ratios compared with conventional EMT synthesized in the presence of 18-crown-6 as template. The organotemplate-free synthesis of EMT with high Si/Al ratios still remains a challenge. 2.4.2. Zeolite Seed Solution-Assisted Approach. The aluminosilicate zeolite ZSM-34 is an intergrowth of offretite (OFF) and erionite (ERI) zeolites containing zeolitic building units of cancrinite (CAN) cages.96−99 ZSM-34 zeolite was first discovered by Rubin et al.96 using the organic template choline [(CH3)3NCH2CH2OH], and later ZSM-34 samples were successfully synthesized in the presence of different diamines (NH2CnH2nNH2, n = 4, 6, 8, 10).100 It is well-known that those zeolites (e.g., CAN, OFF and ERI) composed of CAN cages are natural zeolites, formed in the absence of organic templates. Thus, the synthesis of ZSM-34 without using organic templates is possible. Xiao and co-workers27,29 proposed a new strategy for the organotemplate-free synthesis of ZSM-34. The authors have

Figure 5. Scanning electron microscopy (SEM) image and (inset) Xray diffraction (XRD) patterns of ECR-1 synthesized in the absence of organic template. Reprinted with permission from ref 26. Copyright 2006 American Chemical Society.

molar ratio of Na2O/SiO2 in the synthesis significantly influences the final products of zeolites. When the ratio was 0.33, a pure phase of zeolite Y was formed; when the ratio was 0.28, a mixture of zeolite Y and ECR-1 was crystallized; when the ratio was 0.25, a pure phase of ECR-1 was successfully synthesized; and when the ratio was 0.20, the product was amorphous silica. Furthermore, it was found that the crystallization rate of ECR-1 notably increases with temperature 1526


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ZSM-34 zeolite, and its analogues containing framework B and Ga heteroatoms, show that these ZSM-34 catalysts exhibit higher selectivities for ethylene and propylene (>80%) than ZSM-5 zeolite (150 °C) required for MFI zeolite crystallization and the fast degradation of the TPA+ template under microwave conditions,176 the microwaveassisted synthesis of MFI zeolite membranes is more difficult than that of LTA zeolite membranes. Koegler et al.249 demonstrated microwave-assisted hydrothermal synthesis of silicalite-I zeolite membranes, which were in situ synthesized on a silicon wafer via rapid heating and cooling. Combining microwave heating with secondary growth strategy, Motuzas et al.250 successfully synthesized silicalite-I zeolite membranes on alumina supports with (101) and (001) preferred orientation. Later, they developed an ultrarapid and reproducible synthesis method for thin and good-quality MFI membranes by coupling microwave-assisted synthesis with a rapid template removal method (ozone treatment).251 Microwave-assisted hydrothermal synthesis of zeolite membranes was also extended to the preparation aluminophosphate zeolite membrane.252−254 Mintova et al.252 used microwave heating to synthesize thin films of AlPO4−5 on gold-coated quartz crystal microbalances. The temperature, microwave heating time, power, and aging time are important factors for the control of membrane thickness and crystal orientation. Later, Tsai et al.253 prepared well-aligned SAPO-5 membranes using microwave heating on an anodized aluminum substrate. The effects of various synthetic parameters on the degree of preferred orientation along the c-crystal axis of the AFI structure, and the zeolite coverage on the alumina support, were discussed. Compared with synthesis of zeolite membranes under conventional heating, microwave-assisted synthesis of zeolite membranes led to obvious differences in morphology and composition and a significant improvement in permanence, permselectivity, and compactness, besides the remarkable decreasing of synthetic time. These features are potentially important for industrial applications of zeolite membranes.

alcohol as cosolvents. These alcohols include ethylene glycol, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, and hexanol. They found that the polarity of the alcohols used as cosolvents significantly influenced the morphology of the zeolite crystals. Alcohols with relatively high polarity (dielectric constant) led to isolated single crystals, while alcohols with relatively low polarity resulted in self-stacked crystals.215 The fibers formed by these self-stacked crystals are stable and cannot be destroyed even under strong and prolonged ultrasonication, which suggests the existence of strong chemical bonds between the individual crystals due to condensation of surface Si-OH groups among individual crystals at the early stages of the synthesis. Thus, alcohols with low polarity (dielectric constant) might favor the formation of an abundance of Si-OH groups on the surface of nanocrystals formed in the early stages of microwave-assisted synthesis. Furthermore, diols were also used as cosolvents in microwave-assisted synthesis. In this case, silicalite-1 crystals become longer, narrower, and thinner, with an increasing ratio of the number of the carbon atoms and hydroxyl groups of the diols (Figure 14).216 All these results indicate that the unique microwave heating method strongly influences the growth rates of MFI crystals along different directions. The combination of microwave heating and application of alcohols remarkably changed the growth kinetics of MFI zeolite crystals.141 5.2.3. Microwave-Assisted Hydrothermal Synthesis of Zeolite Membranes. Preparation of zeolite membranes has become a very attractive field due to their wide applications in separation, catalysis, and electronic devices since the mid1990s.217,218 Generally, zeolite membranes can be prepared via three routes: in situ hydrothermal synthesis,219−223 secondary (seeded) growth synthesis,224−227 and vapor-phase transport synthesis.228−230 Notably, the preparation of zeolite membranes under conventional hydrothermal routes generally takes a long time and the quality is not as high as desired. Upon microwave heating, the formation of zeolite particles with small and uniform sizes makes it possible to prepare thin, dense, orientated, and aligned membranes (Figure 15).231−254 Currently, zeolite membranes such as LTA, MFI, AFI, FAU, SOD, and ETS-4 have been successfully synthesized by microwave heating.

5.3. Microwave-Enhanced Ionothermal Synthesis of Zeolites

Although microwave-assisted hydrothermal synthesis of zeolites has obvious advantages compared with conventional hydrothermal synthesis, drawbacks are apparent in that the experiment process is sometimes not safe, and organic templates or volatile solvents still cause problems with excessive pressure production, especially from hot spots. In the previous

Figure 15. Comparative synthesis model of zeolite membrane prepared by microwave heating and conventional heating. Reprinted with permission from ref 248. Copyright 2008 Elsevier. 1537


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microwave radiation time for the first 3 h but remained the same after that. The role of ionic liquids is to retain a sufficient amount of water at high temperature and ambient pressure for the gel crystallization, as well as being hygroscopic, nonvolatile, and efficient at absorbing microwave energy that can lead to a superheated fluid due to inverse heating, together with stabilization of the SDA by an ion-exchange process. 5.3.2. Microwave-Enhanced Ionothermal Synthesis of Zeolite Membranes. Yan and co-workers54 have also reported the microwave-enhanced ionothermal synthesis of extremely well-oriented zeolite coatings on copper-containing aluminum alloys, which are used extensively in the aerospace industry without corrosion problems. They prepared aluminophosphate (AlPO) and Si-substituted aluminophosphate (SAPO) zeolites with the same structure topology (AEL) (Figure 17). They found that the SAPO coating crystallizes

section we have discussed the features of ILs, which have been proven a good medium for absorbing microwaves. Thus, good microwave absorption combined with the low-pressure evolution at high temperature of ILs will open up many possibilities for the use of microwaves in zeolite synthesis.52 5.3.1. Ionothermal Synthesis of Zeolites Assisted by Microwave Radiation. For the first time, Xu et al.52 reported a microwave-enhanced ionothermal synthesis of aluminophosphate zeolites in 2006. They prepared AEL-type aluminophosphate zeolites (AlPO-11 and SAPO-11) in [emim]Br under ionothermal conditions. Products with cubic-like crystals can be exclusively obtained in 20−60 min (Figure 16). On the

Figure 16. SEM micrographs of aluminophosphate molecular sieves (AEL type) prepared by ionothermal synthesis: (a, b) samples after 68 h of crystallization with conventional heating; (c, d) samples after 20 min of crystallization with microwave heating. Synthesis conditions: 150 °C, ambient pressure, ionic liquid [emim]Br. Reprinted with permission from ref 52. Copyright 2006 Wiley−VCH Verlag GmbH & Co. KGaA, Weinheim, Germany.

Figure 17. SEM images of different as-synthesized AEL coatings on AA 2024-T3: (a) AlPO-11 (surface); (b) AlPO-11 (cross section); (c) SAPO-11 (surface, inset is higher magnification); (d) SAPO-11 (cross section, mildly polished surface); (e) SAPO-11 with spin-on BTSMMEL (surface); (f) SAPO-11 with spin-on BTSM-MEL (cross section). Reprinted with permission from ref 54. Copyright 2008 Wiley−VCH Verlag GmbH & Co. KGaA, Weinheim, Germany.

contrary, complete crystallization under conventional heating required 20−40 h. The rapid crystallization of zeolites during microwave-enhanced ionothermal synthesis is attributed to local superheating. Additionally, it seems likely that microwaves can enhance the reaction of fluoride ions with Al species, namely, enhancing the digestion of the reactant into the liquid phase, as well as facilitating the formation of the zeolite structure during ionothermal synthesis. Therefore, the microwave-enhanced ionothermal synthesis of zeolites can be expected to be a promising approach to preparation of zeolites. Recently, Yan and co-workers55 have successfully developed a new strategy for the preparation of silica-based zeolites (MFI) at ambient pressure that combines the advantages of ionothermal synthesis, dry-gel conversion, and microwave radiation, making it a promising, safe, fast, and continuous process for industrial applications. They used microwave heating instead of conventional heating to convert the dried gel precursor (DGP) containing [Bmim]Br as structuredirecting agents to MFI zeolites at ambient pressure. The DGP was successfully converted to MFI crystals after 2 h of microwave radiation at 175 °C at ambient pressure in the presence of excess water. The crystallinity increased with

more slowly but in such a way that it is highly aligned to the surface of the metal, while AlPO coatings crystallize quickly with almost randomly oriented coating. The coatings adhere well to the metal surface, and direct current (dc) polarization results indicate that the coatings make excellent anticorrosion barriers. The success of Yan’s work proves that microwave-enhanced ionothermal synthesis methods can be used as novel, simple, fast, environmentally benign, and safe ways to prepare oriented zeolite membranes.

6. SUMMARY AND PERSPECTIVES The modern synthesis of zeolites mainly involves use of organic templates, addition of solvent, preparation of starting gels, and heating of the gels. Each step could be made greener in the future. 1538


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Biographies

This survey presents a brief overview of recently reported green routes for synthesizing zeolites, including reduction or elimination of organic templates, use of green solvents such as ILs or complete elimination of solvent, and efficient heating of the starting gels. To overcome the disadvantages of using organic templates, nontoxic templates and template recycling steps have been employed in zeolite syntheses. In addition, organotemplate-free syntheses have become a popular and universal methodology for synthesizing zeolites. Particularly, seed-directed synthesis in the absence of organic templates is a general route for synthesizing a series of zeolites. To reduce the aqueous wastes and high pressure required in the synthesis of zeolites, ionic liquids (ILs) as green solvents have been widely used in recent years. Of course, the best way to reduce the aqueous wastes is a solvent-free (solventless) synthetic route. To heat the starting gels efficiently, microwave radiation was used to crystallize zeolites very rapidly. Notably, most green approaches referred to above are separated, and as a consequence, there is always a balance of competing aspects. For example, many kinds of zeolites can be prepared in the absence of solvent but still require the presence of organic templates; zeolite seed solutions assist the synthesis of zeolites without use of organic templates but water is necessary for the solution; microwave-assisted synthesis saves energy and increases efficiency but also can cause high pressure in the presence of low-boiling solvents. Thus, the combination of various green routes may have a promising future for synthesizing zeolites from an industrial perspective. It has been demonstrated that the combination of ionothermal synthesis and microwave heating is a simple, fast, environmentally benign, and safe route for synthesizing zeolites.52,55 However, the combination of solvent-free synthesis and organotemplate-free strategies is still challenging, although this would represent a truly green route,51 as it completely avoids the use of organic templates and solvents. Furthermore, microwave-assisted synthesis of zeolites in the absence of solvents and organic templates would be a simple, fast, low-cost, environmentally benign, and safe route, which completely fulfills the requirements of green chemistry. We believe this is needed to move forward in the field. The solvent-free (solventless) synthesis of zeolites is particularly emphasized. This approach raises many questions in terms of its potential for large-scale applications, including the role of the initial grinding, the mechanism of solvent-free synthesis, the interaction between the organic SDAs (in the case involved) and the silica, and the properties of the products.158 Synthetic chemistry under green conditions is still a fertile ground for fundamental studies of reactivity.

Dr. Xiangju Meng received his B.S. (1999) and Ph.D. (2004) from the College of Chemistry, Jilin University, China. Subsequently, he joined the Catalytic Chemistry Division, Chemical Resources Laboratory, Tokyo Institute of Technology, Japan, for postdoctoral work on the synthesis and applications of nanoporous materials under the guidance of Prof. T. Tatsumi. After postdoctoral work at the National Institute of Advanced Industrial Science and Technology (AIST), Japan, he returned to China and joined Prof. Xiao’s group. He was promoted to associate professor at Zhejiang University in 2009. His research interests include zeolites and heterogeneous catalysis.

Prof. Feng-Shou Xiao received his B.S. and M.S. degrees from the Department of Chemistry, Jilin University, China. From there he moved to the Catalysis Research Center, Hokkaido University, Japan, where he was involved in collaborative research between China (Jilin University and Dalian Institute of Chemical Physics) and Japan. He was a Ph.D. student there for two years, and was awarded his Ph.D. degree at Jilin University in 1990. After postdoctoral work at the University of California at Davis, USA, he joined the faculty at Jilin University in 1994, where he is a full and distinguished professor of Chemistry. Since 2009, He moved to Zhejiang University from Jilin University, and now he is a full and distinguished professor of Chemistry in Zhejiang Univeristy. For his research in porous catalytic materials, Prof. Xiao has been recognized with the National Outstanding Award of Young Scientists of the National Science Foundation of China in 1998 and Thomson Reuters Scientific Research Fronts Award in 2008.

AUTHOR INFORMATION

ACKNOWLEDGMENTS This work was supported by the National High-Tech Research and Development program of China (2013AA065301) and the National Natural Science Foundation of China (21333009, 21273197, and U1162201).

Corresponding Author

*E-mail [email protected]. Notes

The authors declare no competing financial interest. 1539


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(43) Parnham, E. R.; Morris, R. E. Chem. Mater. 2006, 18, 4882. (44) Parnham, E. R.; Morris, R. E. J. Mater. Chem. 2006, 16, 3682. (45) Parnham, E. R.; Morris, R. E. Acc. Chem. Res. 2007, 40, 1005. (46) Drylie, E. A.; Wragg, D. S.; Parnham, E. R.; Wheatley, P. S.; Slawin, A. M. Z.; Warren, J. E.; Morris, R. E. Angew. Chem., Int. Ed. 2007, 46, 7839. (47) Morris, R. E. Chem. Commun. 2009, 2990. (48) Liu, L.; Li, Y.; Wei, H.; Dong, M.; Wang, J.; Slawin, A. M. Z.; Li, J.; Dong, J.; Morris, R. E. Angew. Chem., Int. Ed. 2009, 48, 2206. (49) Wragg, D. S.; Byrne, P. J.; Giriat, G.; Le Ouay, B.; Gyepes, R.; Harrison, A.; Whittaker, A. G.; Morris, R. E. J. Phys. Chem. C 2009, 113, 20553. (50) Wheatley, P. S.; Allan, P. K.; Teat, S. J.; Ashbrook, S. E.; Morris, R. E. Chem. Sci. 2010, 1, 483. (51) Ren, L.; Wu, Q.; Yang, C.; Zhu, L.; Li, C.; Zhang, P.; Zhang, H.; Meng, X.; Xiao, F.-S. J. Am. Chem. Soc. 2012, 134, 15173. (52) Xu, Y.; Tian, Z.; Wang, S.; Hu, Y.; Wang, L.; Wang, B.; Ma, Y.; Hou, L.; Yu, J.; Lin, L. Angew. Chem., Int. Ed. 2006, 45, 3965. (53) Morris, R. E. Angew. Chem., Int. Ed. 2008, 47, 442. (54) Cai, R.; Sun, M.; Chen, Z.; Munoz, R.; O’Neill, C.; Beving, D.; Yan, Y. Angew. Chem., Int. Ed. 2008, 47, 525. (55) Cai, R.; Liu, Y.; Gu, S.; Yan, Y. J. Am. Chem. Soc. 2010, 132, 12776. (56) Barrer, R. M.; Denny, P. J. J. Chem. Soc. 1961, 971. (57) Kerr, G. T.; Kokotailo, G. T. J. Am. Chem. Soc. 1961, 83, 4675. (58) Wadlinger, R. L.; Kerr, G. T.; Rosinski, E. J. U.S. Patent 3,308,069, 1967. (59) Zones, S. I.; Hwang, S.-J. Chem. Mater. 2002, 14, 313. (60) Zones, S. I. U.S. Patent 0,075,656, 2008. (61) Vaughan, D. E. W.; Barrett, M. G. U.S. Patent 4,333,859, 1982. (62) Vaughan, D. E. W. U.S. Patent 4,879,103, 1989. (63) Liu, S.; Li, L.; Li, C.; Xiong, X.; Xiao, F.-S. J. Porous Mater. 2008, 15, 295. (64) Ren, L.; Zhu, L.; Yang, C.; Chen, Y.; Sun, Q.; Zhang, H.; Li, C.; Nawaz, F.; Meng, X.; Xiao, F.-S. Chem. Commun. 2011, 47, 9789. (65) Moscoso, J. G.; Lewis, G. J.; Gisselquist, J. L.; Miller, M. A.; Rohde, L. M. U.S. Patent 6,713,041, 2004. (66) Lewis, G. J.; Miller, M. A.; Moscoso, J. G.; Wilson, B. A.; Knight, L. M.; Wilson, S. T. Stud. Surf. Sci. Catal. 2004, 154, 364. (67) Miller, M. A.; Moscoso, J. G.; Koster, S. C.; Gatter, M. G.; Lewis, G. J. Stud. Surf. Sci. Catal. 2004, 170, 347. (68) Park, M. B.; Lee, Y.; Zheng, A.; Xiao, F.-S.; Nicholas, C. P.; Lewis, G. J.; Hong, S. B. J. Am. Chem. Soc. 2013, 135, 2248. (69) Whitehurst, D. D. U.S. Patent 5,143,879, 1992. (70) Chen, C. Y.; Li, H. X.; Davis, M. E. Microporous Mater. 1993, 2, 17. (71) Tanev, P. T.; Pinnavaia, T. J. Science 1995, 267, 865. (72) Srinivasachar, K.; David, M.; Nerville, J. Biochemistry 1989, 28, 2501. (73) Grose, R. W.; Flanigen, E. M. Belgian Patent 851,066, 1977. (74) Grose, R. W.; Flanigen, E. M. British Patent 574,840, 1980. (75) Grose, R. W.; Flanigen, E. M. U.S. Patent 4,257,885, 1981. (76) Chao, K. Proc. Natl. Sci. Counc., Repub. China 1979, 3, 233. (77) Li, X.; Xiang, S.; Wu, D.; Liu, Y.; Zhang, X.; Liu, S. Chem. J. Chin. Univ. 1981, 2, 517. (78) Shiralkar, V. P.; Clearfield, A. Zeolites 1989, 9, 363. (79) Warrender, S. J.; Wright, P. A.; Zhou, W.; Lightfoot, P.; Camblor, M. A.; Shin, C.-H.; Kim, D. J.; Hong, S. B. Chem. Mater. 2005, 17, 1272. (80) Zhang, L.; Liu, S.; Xie, S.; Xu, L. Microporous Mesoporous Mater. 2012, 147, 117. (81) Ng, E.-P.; Chateigner, D. D.; Bein, T.; Valtchev, V.; Mintova, S. Science 2012, 335, 70. (82) Yokoi, T.; Yoshioka, M.; Tatsumi, T. Angew. Chem., Int. Ed. 2009, 48, 9884. (83) Honda, K.; Yashiki, A.; Itakura, M.; Ide, Y.; Sadakane, M.; Sano, T. Microporous Mesoporous Mater. 2011, 142, 161. (84) Yashiki, A.; Honda, K.; Fujimoto, A.; Shibata, S.; Ide, Y.; Sadakane, M.; Sano, T. J. Cryst. Growth 2011, 325, 96.

REFERENCES (1) Corma, A. Chem. Rev. 1995, 95, 559. (2) Corma, A. Chem. Rev. 1997, 97, 2373. (3) Davis, M. E. Nature 2002, 417, 813. (4) Cundy, C. S.; Cox, P. A. Chem. Rev. 2003, 103, 663. (5) Centi, G.; Perathoner, S. Catal. Today 2009, 143, 145. (6) Huybrechts, D. R. C.; De Bruycker, L.; Jacobs, P. A. Nature 1990, 345, 240. (7) BASF-Dow Chemical-Solvay, Press release, 28 September, 2006. (8) Xu, R.; Pang, W.; Yu, J.; Huo, Q.; Chen, J. Chemistry of Zeolites and Related Porous Materials: Wiley: Singapore, 2007. (9) Breck, D. W. Zeolite Molecular Sieves: Wiley: New York, 1974. (10) Barrer, R. M. Hydrothermal Chemistry of Zeolites: Academic Press: London, 1982. (11) Davis, M. E.; Lobo, R. F. Chem. Mater. 1992, 4, 756. (12) Corma, A.; Davis, M. E. ChemPhysChem 2004, 5, 304. (13) Cundy, C. S.; Cox, P. A. Microporous Mesoporous Mater. 2005, 82, 1. (14) Lee, H.; Zones, S. I.; Davis, M. E. Nature 2003, 425, 385. (15) Trost, B. M. Science 1991, 254, 1471. (16) Tundo, P., Anastas, P. T. Green Chemistry: Challenging Perspectives: Oxford University Press: New York, 1999. (17) http://www.epa.gov/greenchemistry/. (18) Centi, G.; Perathoner, S. Catal. Today 2003, 77, 287. (19) Martinez, C.; Corma, A. Coord. Chem. Rev. 2011, 255, 1558. (20) Wang, J.; Song, J.; Yin, C.; Ji, Y.; Zou, Y.; Xiao, F.-S. Microporous Mesoporous Mater. 2009, 117, 561. (21) Takewaki, T.; Beck, L. W.; Davis, M. E. J. Phys. Chem. B 1999, 103, 2674. (22) Takewaki, T.; Beck, L. W.; Davis, M. E. Top. Catal. 1999, 9, 35. (23) Takewaki, T.; Hwang, S. J.; Yamashita, H.; Davis, M. E. Microporous Mesoporous Mater. 1999, 32, 265. (24) Jones, C. W.; Hwang, S. J.; Okubo, T.; Davis, M. E. Chem. Mater. 2001, 13, 1041. (25) Jones, C. W.; Tsuji, K.; Takewaki, T.; Beck, L. W.; Davis, M. E. Microporous Mesoporous Mater. 2001, 48, 57. (26) Song, J.; Dai, L.; Ji, Y.; Xiao, F.-S. Chem. Mater. 2006, 18, 2775. (27) Wu, Z.; Song, J.; Ji, Y.; Ren, L.; Xiao, F.-S. Chem. Mater. 2008, 20, 357. (28) Xie, B.; Song, J.; Ren, L.; Ji, Y.; Li, J.; Xiao, F.-S. Chem. Mater. 2008, 20, 4533. (29) Zhang, L.; Yang, C.; Meng, X.; Xie, B.; Wang, L.; Ren, L.; Ma, S.; Xiao, F.-S. Chem. Mater. 2010, 22, 3099. (30) Xie, B.; Zhang, H.; Yang, C.; Liu, S.; Ren, L.; Meng, X.; Yilmaz, B.; Müller, U.; Xiao, F.-S. Chem. Commun. 2011, 47, 3945. (31) Zhang, H.; Guo, Q.; Ren, L.; Yang, C.; Zhu, L.; Meng, X.; Li, C.; Xiao, F.-S. J. Mater. Chem. 2011, 21, 9494. (32) Zhang, H.; Yang, C.; Zhu, L.; Meng, X.; Yilmaze, B.; Müller, U.; Feyen, M.; Xiao, F.-S. Microporous Mesoporous Mater. 2012, 155, 1. (33) Majano, G.; Delmotte, L.; Valtchev, V.; Mintova, S. Chem. Mater. 2009, 21, 4184. (34) Ng, E.-P.; Chateigner, D.; Bein, T.; Valtchev, V.; Mintova, S. Science 2012, 335, 70. (35) Iyoki, K.; Kamimura, Y.; Itabashi, K.; Shimojima, A.; Okubo, T. Chem. Lett. 2010, 39, 730. (36) Kamimura, Y.; Chaikittisilp, W.; Itabashi, K.; Shimojima, A.; Okubo, T. Chem.Asian J. 2010, 5, 2182. (37) Kamimura, Y.; Tanahashi, S.; Itabashi, K.; Sugawara, A.; Wakihara, T.; Shimojima, A.; Okubo, T. J. Phys. Chem. C 2011, 115, 744. (38) Kamimura, Y.; Itabashi, K.; Okubo, T. Microporous Mesoporous Mater. 2012, 147, 149. (39) Cooper, E. R.; Andrews, C. D.; Wheatley, P. S.; Webb, P. B.; Wormald, P.; Morris, R. E. Nature 2004, 430, 1012. (40) Parnham, E. R.; Morris, R. E. J. Am. Chem. Soc. 2006, 128, 2204. (41) Parnham, E. R.; Drylie, E. A.; Wheatley, P. S.; Slawin, A. M. Z.; Morris, R. E. Angew. Chem., Int. Ed. 2006, 45, 4962. (42) Parnham, E. R.; Wheatley, P. S.; Morris, R. E. Chem. Commun. 2006, 380. 1540


Chemical Reviews

Review

(85) Zhang, W.; Wu, Y.; Gu, J.; Zhou, H.; Wang, J. Mater. Res. Bull. 2011, 46, 1451. (86) Meng, X.; Xie, B.; Xiao, F.-S. Chin. J. Catal. 2009, 30, 965. (87) Argauer, R. J.; Landolt, G. R. U.S. Patent 3,702,886, 1972. (88) Vaughan, D. E. W.; Strohmaier, K. G. Proc. Int. Zeolite Conf., 7th 1986, 207. (89) Vaughan, D. E. W; Strohmaier, K. G. U.S. Patent 4,657,748, 1987. (90) Leonowicz, M. E.; Vaughan, D. E. W. Nature 1987, 329, 819. (91) Chen, C. S. H.; Schlenker, J. L.; Wentzek, S. E. Zeolites 1996, 17, 393. (92) Gualtieri, A. F.; Ferrari, S.; Galli, E.; Di Renzo, F.; van Beck, W. Chem. Mater. 2006, 18, 76. (93) Martens, J. A.; Jacobs, P. A.; Cartlidge, S. Zeolites 1989, 9, 423. (94) Newsam, J. M.; Treacy, M. M. J.; Vaughan, D. E. W.; Strohmaier, K. G.; Mortier, W. J. Chem. Commun. 1989, 493. (95) Haas, A.; Harding, D. A.; Nee, J. R. D. Microporous Mesoporous Mater. 1999, 28, 325. (96) Rubin, M. K.; Rosinski, E. J.; Plank, C. J. U.S. Patent 4,116,813, 1978. (97) Givens, E. N.; Plank, C. J.; Rosinski, E. J. U.S. Patent 4,079,095, 1978. (98) Givens, E. N.; Plank, C. J.; Rosinski, E. J. U.S. Patent 4,079,096, 1978. (99) Occelli, M. E.; Innes, R. A.; Pollack, S. S.; Sanders, J. V. Zeolites 1987, 7, 265. (100) Vartuli, J. C.; Kennedy, G. J.; Yoon, B. A.; Malek, A. Microporous Mesoporous Mater. 2000, 38, 247. (101) Tsitsishvili, G. V. Adv. Chem. Ser. 1973, 121, 291. (102) Breck, D. W.; Grose, R. W. Adv. Chem. Ser. 1973, 121, 319. (103) Li, S.; Xu, R. Chem. J. Chin. Univ. 1992, 13, 145. (104) Di, Y.; Yu, Y.; Sun, Y.; Yang, X.; Lin, S.; Zhang, M.; Li, S.; Xiao, F.-S. Microporous Mesoporous Mater. 2003, 62, 221. (105) Gies, H.; Gunawardane, R. P. Zeolites 1987, 7, 442. (106) Morris, R. E.; Weigel, S. J.; Henson, N. J.; Bull, L. M.; Janicke, M. T.; Chmelka, B. F.; Cheetham, A. K. J. Am. Chem. Soc. 1994, 116, 11849. (107) Asensi, M. A.; Martínez, A. Appl. Catal., A 1999, 183, 155. (108) Lee, S.; Shin, C.; Hong, S. B. J. Catal. 2004, 223, 200. (109) Pinar, A. B.; Márquez-Á lvarez, C.; Grande-Casas, M.; PérezPariente, J. J. Catal. 2009, 263, 258. (110) Rakoczy, R. A.; Breuninger, M.; Hunger, M.; Traa, Y.; Weitkamp, J. Chem. Eng. Technol. 2002, 25, 273. (111) Guo, G.; Sun, Y.; Long, Y. Chem. Commun. 2000, 1893. (112) Pál-Borbély, G.; Szegedi, Á .; Beyer, H. K. Microporous Mesoporous Mater. 2000, 35−36, 573. (113) Schreyeck, L.; Caullet, P.; Mougenel, J. C.; Guth, J. L.; Marler, B. Microporous Mater. 1996, 6, 259. (114) Kim, T. J.; Ahn, W. S.; Hong, S. B. Microporous Mater. 1996, 7, 35. (115) Roth, W. J.; Dorset, D. L. Struct. Chem. 2010, 21, 385. (116) Ikeda, T.; Akiyama, Y.; Oumi, Y.; Kawai, A.; Mizukami, F. Angew. Chem., Int. Ed. 2004, 43, 4892. (117) Suzuki, Y.; Wakihara, T.; Itabashi, K.; Ogura, M.; Okubo, T. Top. Catal. 2009, 52, 67. (118) Kerr, G. T. J. Phys. Chem. 1968, 72, 1385. (119) Kasahara, S.; Itabashi, K.; Igawa, K. Stud. Surf. Sci. Catal. 1986, 28, 185. (120) Edelman, R. D.; Kudalkar, D. V.; Ong, T.; Warzywoda, J.; Thompson, R. W. Zeolites 1989, 9, 496. (121) Gora, L.; Thompson, R. W. Zeolites 1995, 15, 526. (122) Gora, L.; Streletzky, K.; Thompson, R. W.; Phillies, G. D. G. Zeolites 1997, 18, 119. (123) Thompson, R.; Karge, H. G.; Weitkamp, J. Molecular Sieves Synthesis; Springer: New York, 1998. (124) Boggs, R. C.; Howard, D. G.; Smith, J. V.; Klein, G. L. Am. Mineral. 1993, 78, 822. (125) Vortmann, S.; Marler, B.; Gies, H.; Daniels, P. Microporous Mater. 1995, 4, 111.

(126) Lee, G. S.; Zones, S. I. J. Solid State Chem. 2002, 167, 289. (127) Baerlocher, C.; McCusker, L. B.; Olson, D. H. Atlas of Zeolite Framework Types, 6th ed.; Elsevier: Amsterdam, 2007. (128) Jones, C. W.; Zones, S. I.; Davis, M. E. Appl. Catal., A 1999, 181, 289. (129) Yoo, K.; Kashfi, R.; Gopal, S.; Smirniotis, P. G.; Gangoda, M.; Bose, R. N. Microporous Mesoporous Mater. 2003, 60, 57. (130) Gopal, S.; Yoo, K.; Smirniotis, P. G. Microporous Mesoporous Mater. 2001, 49, 149. (131) Corbin, D. R.; Abrams, L.; Jones, G. A.; Eddy, M. M.; Harrison, W. T. A.; Stucky, G. D.; Cox, D. E. J. Am. Chem. Soc. 1990, 112, 4821. (132) Choo, S.; Hong, S. K.; Kevan, L. J. Phys. Chem. B 2001, 105, 7730. (133) Lawton, L.; Bennett, J. M.; Schlenker, J. L.; Rubin, M. K. J. Chem. Soc. Chem. Commun. 1993, 894. (134) Wikes, J. S.; Zaworotko, M. J. Chem. Commun. 1992, 965. (135) Ranke, J.; Stolte, S.; Störmann, R.; Arning, J.; Jastorff, B. Chem. Rev. 2007, 107, 2183. (136) Binnemans, K. Chem. Rev. 2007, 107, 2592. (137) Pârvulescu, V. I.; Hardacre, C. Chem. Rev. 2007, 107, 2695. (138) Plechkova, N. V.; Seddon, K. R. Chem. Soc. Rev. 2008, 37, 123. (139) Ma, Z.; Yu, J.; Dai, S. Adv. Mater. 2010, 22, 261. (140) Welton, T. Chem. Rev. 1999, 99, 2071. (141) Xu, R.; Pang, W.; Huo, Q. Modern Inorganic Synthetic Chemistry; Elsevier: Amsterdam, 2011. (142) Camblor, M. A.; Villaescusa, L. A.; Diaz-Cabanas, M. J. Top. Catal. 1999, 9, 59. (143) Morris, R. E.; Burton, A.; Bull, L. M.; Zones, S. I. Chem. Mater. 2004, 16, 2844. (144) Zones, S. I.; Darton, R. J.; Morris, R.; Hwang, S. J. J. Phys. Chem. B 2005, 109, 652. (145) Wragg, D. S.; Slawin, A. M. Z.; Morris, R. E. Solid State Sci. 2009, 11, 411. (146) Ma, H.; Tian, Z.; Xu, R.; Wang, B.; Wei, Y.; Wang, L.; Xu, Y.; Zhang, W.; Lin, L. J. Am. Chem. Soc. 2008, 130, 8120. (147) Wang, L.; Xu, Y.; Wei, Y.; Duan, J.; Chen, A.; Wang, B.; Ma, H.; Tian, Z.; Lin, L. J. Am. Chem. Soc. 2006, 128, 7432. (148) Xing, H.; Li, J.; Yan, W.; Chen, P.; Jin, Z.; Yu, J.; Dai, S.; Xu, R. Chem. Mater. 2008, 20, 4179. (149) Wei, Y.; Tian, Z.; Gies, H.; Xu, R.; Ma, H.; Pei, R.; Zhang, W.; Xu, Y.; Wang, L.; Li, K.; Wang, B.; Wen, G.; Lin, L. Angew. Chem., Int. Ed. 2010, 49, 5367. (150) Wang, L.; Xu, Y.; Wang, B.; Wang, S.; Yu, J.; Tian, Z.; Lin, L. Chem.Eur. J. 2008, 14, 10551. (151) Ma, H.; Xu, R.; You, W.; Wen, G.; Wang, S.; Xu, Y.; Wang, B.; Wang, L.; Wei, Y.; Xu, Y.; Zhang, W.; Tian, Z.; Lin, L. Microporous Mesoporous Mater. 2009, 120, 278. (152) Ma, Y.; Xu, Y.; Wang, S.; Wang, B.; Tian, Z.; Yu, J.; Lin, L. Chem. J. Chin. Univ. 2006, 27, 739. (153) Wheatley, P. S.; Allan, P. K.; Teat, S. J.; Ashbrook, S. E.; Morris, R. E. Chem. Sci. 2010, 1, 483. (154) Tanaka, K.; Toda, F. Chem. Rev. 2000, 100, 1025 and references therein. (155) Walsh, P. J.; Li, H.; de Parrodi, C. A. Chem. Rev. 2007, 107, 2503. (156) Hobbs, H. R.; Thomas, N. R. Chem. Rev. 2007, 107, 2786. (157) Martins, M. A. P.; Frizzo, C. P.; Moreira, D. N.; Buriol, L.; Machado, P. Chem. Rev. 2009, 109, 4140. (158) Morris, R. E.; James, S. L. Angew. Chem., Int. Ed. 2013, 52, 2163. (159) Zhang, P.; Wang, L.; Ren, L.; Zhu, L.; Sun, Q.; Zhang, J.; Meng, X.; Xiao, F.-S. J. Mater. Chem. 2011, 21, 12026. (160) Lin, J.; Lin, R.; Cheng, X.; Zhang, J.; Chen, X. Chem. Commun. 2011, 47, 9185. (161) Biswal, B. P.; Chandra, S.; Kandambeth, S.; Lukose, B.; Heine, T.; Banerjee, R. J. Am. Chem. Soc. 2013, 135, 5328. (162) Xu, W.; Dong, J.; Li, J.; Wu, F. J. Chem. Soc., Chem. Commun. 1990, 755. (163) Rao, P. R. H. P.; Matsutaka, M. Chem. Commun. 1996, 1441. 1541


Chemical Reviews

Review

(164) Schmidt, F. Appl. Catal., A 2001, 221, 15. (165) Althoff, R.; Unger, K.; Schüth, F. Microporous Mater. 1994, 2, 563. (166) Deforth, U.; Unger, K. K.; Schüth, F. Microporous Mater. 1997, 9, 287. (167) Duan, F.; Li, J.; Chen, P.; Yu, J.; Xu, R. Microporous Mesoporous Mater. 2009, 126, 26. (168) Jin, Y.; Sun, Q.; Qi, G.; Yang, C.; Xu, J.; Chen, F.; Meng, X.; Deng, F.; Xiao, F.-S. Angew. Chem., Int. Ed. 2013, 52, 9172. (169) Wang, C.; Wang, Y.; Liu, H.; Xie, Z.; Liu, Z. J. Catal. 2010, 271, 386. (170) Kingstone, H. M.; Haswell, S. J. Microwave-Enhanced Chemistry: American Chemical Society: Washington, DC, 1997. (171) Tompsett, G. A.; Conner, W. C.; Yngvesson, K. S. ChemPhysChem 2006, 7, 296. (172) Ryan, M. A.; Tinnesand, M. Introduction to Green Chemistry: American Chemical Society: Washington, DC, 2002. (173) Rao, K. J.; Vaidhyanathan, B.; Ganguli, M.; Ramakrishnan, P. A. Chem. Mater. 1999, 11, 882. (174) Katsuki, H.; Furuta, S.; Komarneni, S. J. Porous Mater. 2001, 8, 5. (175) Xu, X.; Yang, W.; Liu, J.; Lin, L. Sep. Purif. Technol. 2001, 25, 241. (176) Girnus, I.; Jancke, K.; Vetter, R.; Richtermendau, J.; Caro, J. Zeolites 1995, 15, 33. (177) Stenzel, C.; Brinkmann, M.; Müller, J.; Schertlen, R.; Venot, Y.; Wiesbeck, W. J. Microwave Power Electromagn. Energy 2001, 36, 155. (178) Slangen, P. M.; Jansen, J. C.; van Bekkum, H. Microporous Mater. 1997, 9, 259. (179) Zhao, J. P.; Cundy, C. S.; Plaisted, R. J.; Dwyer, J. Proc. Int. Zeolite Conf., 12th 1999, 1591. (180) Chu, P.; Dwyer, F. G.; Vartuli, X. U.S. Patent 4,778,666, 1988. (181) Cundy, C. S. Collect. Czech. Chem. Commun. 1998, 63, 1699. (182) Girnus, I.; Jancke, K.; Vetter, R.; Richtermendau, J.; Caro, J. Zeolites 1995, 15, 33. (183) Uguina, M. A.; Serrano, D. P.; Sanz, R.; Castillo, E. Proc. Int. Zeolite Conf., 12th 1999, 1917. (184) Pilter, Z.; Szabo, S.; Hasznos-Nezdei, M.; Pallai-Varsanyi, E. Microporous Mesoporous Mater. 2000, 40, 257. (185) Cheng, Z.; Wan, H.; Liu, Z. Chin. J. Chem. 2004, 22, 1454. (186) Bonaccorsi, L.; Proverbio, E. Mater. Res. Innov. 2004, 8, 53. (187) Bonaccorsi, L.; Proverbio, E. J. Cryst. Growth 2003, 247, 555. (188) Sathupunya, M.; Gulari, E.; Wongkasemjit, S. J. Eur. Ceram. Soc. 2003, 23, 1293. (189) Lim, H. M.; Ahn, B. G.; Jung, S.-J.; Lee, S. H. Adv. Technol. Mater. Mater. Process. J. 2003, 6, 104. (190) Sathupunya, M.; Gulari, E.; Wongkasemjit, S. J. Eur. Ceram. Soc. 2002, 22, 2305. (191) Arafat, A.; Jansen, J. C.; Ebaid, A. R.; Vanbekkum, H. Zeolites 1993, 13, 162. (192) Kita, H.; Harada, T.; Shibata, T.; Lin, X.; Okamoto, K. Abstr. Pap.Am. Chem. Soc. 2001, 222, 36. (193) de Araujo, L. R. G.; Cavalcante, C. L.; Farias, K. M., Jr.; Guedes, I.; Sasaki, J. M.; Freire, P. T. C.; Melo, F. E. A.; Mendes-Filho, J. Mater. Res. 1999, 2, 105. (194) Cheng, Z.; Chao, Z.; Wan, H. Acta Phys.-Chim. Sin. 2003, 19, 487. (195) Slangen, P. M.; Jansen, J. C.; Van Bekkum, H.; Hofland, G. W.; Van der Ham, F.; Witkamp, G. J. Proc. Int. Zeolite Conf., 12th 1999, 1553. (196) Zhao, J. P.; Cundy, C.; Dwyer, J. Proc. Int. Zeolite Conf., 11th 1996, 181. (197) Kooyman, P. J.; van der Waal, P.; van Bekkum, H. Zeolites 1997, 18, 50. (198) Cundy, C. S.; Forrest, J. O.; Plaisted, R. J. Microporous Mesoporous Mater. 2003, 66, 143. (199) Carmona, J. G.; Clemente, R. R.; Moreles, J. G. Zeolites 1997, 18, 340.

(200) Kodaira, T.; Miyazawa, K.; Ikeda, T.; Kiyozumi, Y. Microporous Mesoporous Mater. 1999, 29, 329. (201) Cejka, J.; Zilkova, N. Chem. Listy 2000, 94, 278. (202) Holzl, M.; Mintova, S.; Bein, T. J. Mater. Chem. 2004, 14, 2972. (203) Kunii, K.; Narahara, K.; Yamanaka, S. Microporous Mesoporous Mater. 2002, 52, 159. (204) Park, M.; Komarneni, S. Microporous Mesoporous Mater. 1998, 20, 39. (205) Du, H.; Fang, M.; Xu, W.; Meng, X.; Pang, W. J. Mater. Chem. 1997, 7, 551. (206) Jhung, S. H.; Chang, C.; Hwang, J. S.; Park, S. E. Microporous Mesoporous Mater. 2003, 64, 33. (207) Cresswell, S. L.; Parsonage, J. R.; Riby, P. G.; Thomas, M. J. K. J. Chem. Soc., Dalton Trans. 1995, 13, 2315. (208) Lohse, U.; Bertram, R.; Jancke, K.; Kurzawski, I.; Parlitz, B.; Loffler, E.; Schreier, E. J. Chem. Soc., Faraday Trans. 1995, 91, 1163. (209) Lohse, U.; Bruckner, A.; Kintscher, K.; Parlitz, B.; Schreier, E. J. Chem. Soc., Faraday Trans. 1995, 91, 1173. (210) Lohse, U.; Brueckner, A.; Schreier, E.; Bertram, R.; Jaenchen, J.; Fricke, R. Microporous Mater. 1996, 7, 139. (211) Hwang, Y. K.; Chang, J.-S.; Park, S. E.; Kim, D. S.; Kwon, Y.U.; Jhung, S. H.; Hwang, J.-S.; Park, M. S. Angew. Chem., Int. Ed. 2005, 44, 556. (212) Hwang, Y. K.; Jin, T.; Kim, J. M.; Kwon, Y.-U.; Park, S. E.; Chang, J.-S. J. Nanosci. Nanotechnol. 2006, 8, 1786. (213) Xu, C.-H.; Jin, T.; Jhung, S. H.; Chang, J.-S.; Hwang, J.-S.; Park, S. E. Catal. Today 2006, 111, 366. (214) Chen, X.; Yan, W.; Shen, W.; Yu, J.; Cai, X.; Xu, R. Microporous Mesoporous Mater. 2007, 104, 296. (215) Chen, X.; Yan, W.; Cai, X.; Yu, J.; Xu, R. Microporous Mesoporous Mater. 2009, 119, 217. (216) Chen, X.; Yan, W.; Cai, X.; Xu, R. Microporous Mesoporous Mater. 2010, 131, 45. (217) Bein, T. Chem. Mater. 1996, 8, 1636. (218) Lew, C. M.; Cai, R.; Yan, Y. Acc. Chem. Res. 2010, 43, 210. (219) Yan, Y.; Davis, M. E.; Gavalas, G. R. Ind. Eng. Chem. Res. 1995, 34, 1652. (220) Yan, Y.; Chaudhuri, S. R.; Sarka, A. Chem. Mater. 1996, 8, 473. (221) Dong, J.; Lin, Y. S. Ind. Eng. Chem. Res. 1998, 37, 2404. (222) Wang, Z.; Yan, Y. Chem. Mater. 2001, 13, 1101. (223) Tuan, V. A.; Li, S.; Falconer, J. L.; Noble, R. D. Chem. Mater. 2002, 14, 489. (224) Gouzinis, A.; Tsapatsis, M. Chem. Mater. 1998, 10, 2497. (225) Lovallo, M. C.; Gouzinis, A.; Tsapatsis, M. AIChE J. 1998, 44, 1903. (226) Lai, Z. P.; Tsapatsis, M.; Nicolich, J. R. Adv. Funct. Mater. 2004, 14, 716. (227) Choi, J.; Ghosh, S.; Lai, Z. P.; Tsapatsis, M. Angew. Chem., Int. Ed. 2006, 45, 1154. (228) Dong, J.; Dou, T.; Zhao, X.; Gao, L. Chem. Commun. 1992, 1056. (229) Tsay, C. S.; Chiang, A. S. T. AIChE J. 2000, 46, 616. (230) Thoma, S. G.; Trudell, D. E.; Bonhomme, F.; Nenoff, T. M. Microporous Mesoporous Mater. 2001, 50, 33. (231) Girnus, I.; Pohl, M. M.; Richtermendau, J.; Schneider, M.; Noack, M.; Venzke, D.; Caro, J. Adv. Mater. 1995, 7, 711. (232) Mintova, S.; Mo, S.; Bein, T. Chem. Mater. 1998, 10, 4030. (233) Han, Y.; Ma, H.; Qui, S.; Xiao, F.-S. Microporous Mesoporous Mater. 1999, 30, 321. (234) Xu, X.; Yang, W.; Liu, J.; Lin, L. Sep. Purif. Technol. 2001, 25, 241. (235) Chen, X.; Yang, W.; Liu, J.; Xu, X.; Huang, A.; Lin, L. J. Mater. Sci. Lett. 2002, 21, 1023. (236) Xu, X.; Yang, W.; Liu, J.; Lin, L. Chin. J. Catal. 2001, 22, 99. (237) Li, Y.; Liu, J.; Yang, W. J. Membr. Sci. 2006, 281, 646. (238) Xu, X.; Yang, W.; Liu, J.; Lin, L. Chin. Sci. Bull. 2000, 45, 1179. (239) Dong, Q.; Xu, N.; Shi, J. Huagong Xuebao 2001, 52, 749. (240) Huang, L.; Wang, Z.; Wang, H.; Sun, J.; Li, Q.; Zhao, D.; Yan, Y. Microporous Mesoporous Mater. 2001, 48, 73. 1542


Chemical Reviews

Review

(241) Julbe, A.; Motuzas, J.; Cazevielle, F.; Volle, G.; Guizard, C. Sep. Purif. Technol. 2003, 32, 139. (242) Xu, X.; Yang, W.; Liu, J.; Lin, L. Adv. Mater. 2000, 12, 195. (243) Weh, K.; Noack, M.; Sieber, I.; Caro, J. Microporous Mesoporous Mater. 2002, 54, 27. (244) Chen, X.; Yang, W.; Liu, J.; Lin, L. J. Mater. Sci. 2004, 39, 671. (245) Xu, X.; Bao, Y.; Song, C.; Yang, W.; Liu, J.; Lin, L. Microporous Mesoporous Mater. 2004, 75, 173. (246) Chen, X.; Yang, W.; Liu, J.; Lin, L. J. Mater. Sci. 2005, 55, 201. (247) Madhusoodana, C. D.; Das, R. N.; Kameshima, Y.; Okada, K. Trans. Mater. Res. Soc. Jpn. 2004, 29, 2293. (248) Li, Y.; Yang, W. J. Membr. Sci. 2008, 316, 3. (249) Koegler, J. H.; Arafat, A.; van Bekkum, H.; Jansen, J. C. Stud. Surf. Sci. Catal. 1997, 105, 2163. (250) Motuzas, J.; Julbe, A.; Noble, R. D.; van der Lee, A.; Beresnevicius, Z. J. Microporous Mesoporous Mater. 2006, 92, 259. (251) Motuzas, J.; Heng, S.; Lau, P. P. S. Z.; Yeung, K. L.; Beresnevicius, Z. J.; Julbe, A. Microporous Mesoporous Mater. 2007, 99, 197. (252) Mintova, S.; Mo, S.; Bein, T. Chem. Mater. 1998, 10, 4030. (253) Tsai, T. G.; Shih, H. C.; Liao, S. J.; Chao, K. J. Microporous Mesoporous Mater. 1998, 22, 333. (254) Coutinho, D.; Losilla, J. A.; Balkus, K. J. Microporous Mesoporous Mater. 2006, 90, 229.

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