Zeolite Synthesis from a Charge Density Perspective: The Charge

Nov 12, 2014 - ... Gregory J. Lewis‡, and Suk Bong Hong†. † Center for Ordered Nanoporous Materials Synthesis, Department of Chemical Engineerin...
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Zeolite Synthesis from a Charge Density Perspective: The Charge Density Mismatch Synthesis of UZM‑5 and UZM‑9 Min Bum Park,† Donghui Jo,† Him Chan Jeon,† Christopher P. Nicholas,‡ Gregory J. Lewis,*,‡ and Suk Bong Hong*,† †

Center for Ordered Nanoporous Materials Synthesis, Department of Chemical Engineering and School of Environmental Science and Engineering, POSTECH, Pohang 790-784, Korea ‡ New Materials Research, UOP LLC, A Honeywell Company, Des Plaines, Illinois 60017, United States S Supporting Information *

ABSTRACT: A charge density model of aluminosilicate zeolite synthesis is presented. This model has been applied to the charge density mismatch (CDM) synthesis of UZM-5 and UZM-9 zeolites at 150 and 100 °C, respectively, using the same synthesis mixture that includes tetraethylammonium (TEA+), tetramethylammonium (TMA+), and Na+ ions as structure-directing agents (SDAs). It allows a seamless description of the contributions of both the hydroxide and SDA components of the CDM barrier to zeolite synthesis. The syntheses are described as temperature-driven confrontations with the CDM barrier, resulting in disproportionation to solution and solid products with diverging charge densities. The presence of the CDM barrier and this tunable disproportionation in charge density, along with the suitable choice of SDA concentrations, allows a flexible and cooperative participation of SDAs, as the synthesis medium initially forms aluminosilicate networks that maximize Coulombic stabilization under the conditions at hand. The UZM-5 synthesis at 150 °C is characterized by much higher fractional Si and Al yields (0.85 Si and 0.94 Al vs 0.30 Si and 0.70 Al) and a higher Si/Al ratio (ca. 7 vs 3) compared to UZM-9 synthesis at 100 °C. Unlike the latter case, TEA+ plays an important role in the nucleation of UZM-5. However, TMA+ was found to be essential for the nucleation of both zeolites. While Na+ is required to crystallize UZM-9, the nucleation rate of UZM-5 is about twice as fast in the absence of Na+. On the other hand, the crystal growth rate of this smallpore zeolite is over 10 times faster with Na+ present, giving a considerably larger crystallite size.

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INTRODUCTION Zeolites are crystalline microporous aluminosilicate networks built of corner-sharing [SiO4/2] and [AlO4/2]− tetrahedra, conforming to the general formula A+[SinAlO2(n+1)]−, where A+ is a charge-balancing cation that resides within the zeolite pores, and the portion in brackets represents the negatively charged aluminosilicate framework with an Si/Al ratio of n. Related to the Si/Al ratio is the framework charge density (FWCD) given by −Al/(Si + Al) or −1/(n + 1), since each [AlO4/2]− tetrahedron introduces a single negative charge. Featuring uniform channels and cavities, with dimensions generally smaller than 20 Å, and ion-exchange properties that facilitate wide compositional diversity, zeolites have found utility as catalysts and adsorbents in the refining, petrochemical, separation, and environmental remediation industries. From a synthetic perspective, A+ is considered to play a structuredirecting role in zeolite crystallization, since zeolite void spaces form around this framework charge-balancing cation and occlude it. Early zeolite syntheses, such as those that yielded zeolites A (framework type LTA) and X (FAU), were conducted using basic alkali aluminosilicate gels, with the alkali cations serving as a structure-directing agent (SDA), yielding low Si/Al ratio, high FWCD aluminosilicates.1−4 The discovery that organoammonium cations could also fulfill the role of SDA © 2014 American Chemical Society

led to more silica-rich, lower FWCD materials like zeolite beta (*BEA) and ZSM-5 (MFI), culminating with the synthesis of neutral, pure-silica molecular sieves.5−7 Consequently, much attention has focused on designing new and more complex quaternary ammonium ions in order to achieve a “hand-inglove” fit between the organic SDA and the zeolite pore, i.e., the template effect.8−15 While this approach continues to yield a number of beautiful novel zeolite structures, the resulting solids tend to be silica-rich with low charge densities and are often commercially unfeasible from a manufacturing perspective due to the high cost of organic SDAs employed. The charge density mismatch (CDM) approach to zeolite synthesis is a rational synthesis strategy that relies on cooperation between multiple SDAs to make a single zeolite structure.16−23 This combinatorial SDA strategy is at odds with the traditional notion of the so-called template effect, because the use of multiple SDAs could lead to the crystallization of more than one zeolite structure. To avoid such an outcome, the CDM approach seeks to gain control over the crystallization process by starting with a synthesis mixture that cannot Received: May 26, 2014 Revised: October 22, 2014 Published: November 12, 2014 6684

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cally more effective for providing the CDM barrier because its concentration increases with increasing hydroxide level. To induce zeolite crystallization from the CDM synthesis mixture, one must break down the CDM barrier. This can be accomplished by the addition of one or more higher charge density SDAs, such as Li+, Na+, and tetramethylammonium (TMA+) ions that are more suitable for stabilizing a high FWCD aluminosilicate network. These are designated the crystallization SDAs. The opportunity for zeolite crystallization via the cooperation of multiple SDAs presents itself and seems to be required, but the actual achievement of such cooperation requires one to perform a statistical mechanical balancing act. One must balance the probability that aluminosilicate anions will mostly “see” the CDM SDA, thus keeping the CDM barrier largely intact, with the probability that they “see” the crystallization SDAs and then experience opportunities to condense into an extended network. Consideration of the desired zeolite synthesis conditions provides guidance on how to achieve this balance. The crystallization of a single zeolite structure from multiple SDAs is essentially a competition among the CDM SDA and crystallization SDAs for incorporation into the zeolite pores in a charge-balancing role. To allow all SDAs access to all aluminosilicate species, therefore, it is best to conduct this competition in solution. This requirement entails the strict control of the concentrations of potent crystallization SDAs, which can induce extensive solid or gel formation if used too liberally. Clear solution synthesis mixtures can be maintained if potent crystallization SDAs are added at substoichiometric levels with respect to the Al content, typically at 0.5 equiv per Al or less, usually as halide salts. These low concentrations of crystallization SDAs favor cooperation between multiple SDAs, not only because they are not present in sufficient amounts to dominate or complete zeolite crystallization by themselves but also because they need assistance from other SDAs, often from the CDM SDA, to promote significant solid formation/crystallization. As such, the CDM aluminosilicate solution perturbed with low levels of crystallization SDAs results in a solution with the CDM barrier intact. Finally, the CDM barrier is further attacked by heating the synthesis mixture, resulting in condensation and ultimately the crystallization of one particular zeolite structure, when the temperature is sufficiently high. UZM-9 (LTA) and UZM-5 (UFI) are both zeolites synthesized by the CDM approach and are known to crystallize from the same aluminosilicate solution using TEA+ as a CDM SDA, together with TMA+ and Na+ ions as crystallization SDAs.16,17,20,26−31 However, UZM-5 is synthesized at 150 °C, while UZM-9 is synthesized at 100 °C, and Figure 1 shows that similar synthesis conditions have led to two structures that have several features in common, including lta- and d4r-cage building units. While UZM-9 has a three-dimensional eight-ring pore system, UZM-5 has the same pore system in two-dimensions, but not along the c axis, because the lta-cages are capped by wbc-cages. Temperature is one of the important synthesis parameters governing the phase selectivity of zeolite crystallization, both with and without organic SDA present.32−36 To our knowledge, however, there are few examples where the influence of this thermodynamic variable on the role of SDAs, especially organic ones, in the nucleation and crystal growth processes of zeolites has been clearly elucidated. Here, we address this issue during the course of the CDM synthesis of UZM-5 and UZM-9 in the simultaneous presence of TEA+, TMA+, and Na+ as SDAs. We present a model of zeolite

crystallize by itself. Such a CDM synthesis mixture is an aluminosilicate solution characterized by a low Si/Al ratio (ca. 1−10) that has the potential to form a relatively high FWCD aluminosilicate network. Simultaneously, it also contains a large, low charge density SDA, such as tetrapropylammonium or tetraethylammonium (TEA+), designated the CDM SDA, as the only option to balance the negative charge associated with Al in the aluminosilicate network that could be formed from this aluminosilicate solution. The CDM SDA is usually the sole hydroxide source for this aluminosilicate solution. Due to the charge density mismatch between the low charge density CDM SDA and the potentially high FWCD aluminosilicate network that can form, attempts to crystallize zeolites via the condensation of aluminosilicate anions in the CDM synthesis mixture at typical zeolite synthesis temperatures merely yield solutions; no net extended condensation or solid formation is observed.16,17 Inherent in the CDM synthesis mixture is this barrier to all solid formation, amorphous or crystalline, which we designate the CDM barrier. The CDM barrier is electrostatic in nature and is provided by the CDM SDA and the mismatch situation described above. Condensation of soluble aluminosilicate species to form solid products is driven by the Coulombic stabilization associated with the formation of a charged aluminosilicate network. The aluminosilicate network grows as incorporated charge balancing cations provide the Coulombic stabilization proportional to 1/r, where r is the distance between the charges, that on the cation and that on the negatively charged framework. The large cationic CDM SDAs cannot provide these interactions necessary for aluminosilicate network formation, mainly due to the poor Coulombic stabilization. Moreover, their required frequency to balance charge on a highly negative charged network literally put them in each other’s way, creating long-distance interactions that provide little, if any, Coulombic stabilization. Hence, the CDM barrier acts to keep the aluminosilicate synthesis mixture in solution during the course of zeolite synthesis. The CDM barrier is additionally affected by the hydroxide content of the CDM synthesis mixture. It is well-known in oxometalate chemistry that once the pH is on the negative side of the point of zero charge (pzc) of an oxide, that addition of hydroxide serves to depolymerize or reduce the nuclearity of the oxoanions, while simultaneously increasing the charge density, i.e., the negative charge per metal atom. A clear example is illustrated by the vanadate speciation shown in Scheme 1.24 At the pzc (pH = 1−2), V2O5 is a neutral solid that Scheme 1. Vanadate Species at Different Hydroxide Levels in Aqueous Solution

is depolymerized continuously to smaller vanadate species upon hydroxide addition. The negative charge per V atom increases to −0.6 for V10O286−, −2.0 for V2O74−, and −3.0 for VO43−. Aluminosilicate solutions exhibit much more complicated speciation but exhibit the same trend with hydroxide addition that produces smaller, more highly charged oligomers.25 The higher charge on the aluminosilicate species serves to increase the charge density mismatch between the aluminosilicate species in the synthesis mixture and the target solid aluminosilicate product, making the CDM barrier even more formidable. Simultaneously, the CDM SDA becomes statisti6685

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Figure 1. UFI (left) and LTA (right) structures and their building units. is similar to that of the mother liquor of fully crystallized Na-UZM-9 isolated after 9 days of heating at 100 °C, was prepared using mass balance based on the elemental analysis of the isolated product, assuming that the rest of the synthesis mixture remained in the mother liquor. This aluminosilicate solution with a composition of 25.9TEAOH·0.5Al2O3·18.5SiO2·0.99TMACl·0.64NaCl·794H2O was further digested at 125, 150, 175, and 200 °C for various times. Analytical Methods. Powder X-ray diffraction (XRD) patterns were recorded on a PANalytical X’Pert diffractometer (Cu Kα radiation) with an X’Celerator detector. The relative crystallinities of a series of solid products recovered after heating at 150 °C for different times were determined by comparing the areas of a rather intense Xray peak around 2θ = 10.2°, corresponding to the (110) reflection of the UFI structure,37 with that of a fully crystallized sample. The yield of each product is given in terms of the fractional conversions of Si and Al from the original synthesis mixture into the solid product. Additionally, these solid yields were multiplied by the relative crystallinity in order to show the fractions of Si and Al residing in the crystalline product. Crystal morphology and average size were determined by a JEOL JSM-6510 scanning electron microscope (SEM). Thermogravimetric analyses (TGA) were performed on an SII EXSTAR 6000 thermal analyzer, where the weight losses related to the combustion of organic SDAs were further confirmed by differential thermal analyses (DTA) using the same analyzer. Elemental analysis for Si, Al, and Na was carried out by a Jarrell-Ash Polyscan 61E inductively coupled plasma (ICP) spectrometer in combination with a PerkinElmer 5000 atomic absorption spectrophotometer. The C, H, and N contents of the samples were analyzed by using a Vario EL III elemental organic analyzer. Solution 13C NMR spectra were recorded in 5 mm quartz tubes using a Bruker DRX-500 spectrometer at a 13C frequency of 125.77 MHz with a π/6 rad pulse length of 3.0 μs, a recycle delay of 2 s, and acquisition of ca. 1000 pulse transients. 13C chemical shifts are referenced relative to TMS.

synthesis from a charge density point of view that allows us to better describe the nature of the CDM barrier and the progress of the synthesis. This model has been used to interpret the effects of varying the temperature used to confront the CDM barrier, including how the CDM barrier evolves and how this influences SDA cooperation in a combinatorial SDA system.

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EXPERIMENTAL SECTION

Synthesis. A clear synthesis solution with the composition 8.0TEAOH·xTMACl·yNaCl·0.5Al2O3·8.0SiO2·240H2O, where x and y are varied between 0 ≤ x and y ≤ 1.0, was prepared by combining TMACl (97%, Aldrich), TEAOH (35% aqueous solution, Sachem), NaCl (≥99.5%, Aldrich), aluminum tri-sec-butoxide (Al[O(s-Bu)]3, 97%, Aldrich), tetraethylorthosilicate (TEOS, 98%, Aldrich), and deionized water. In a typical synthesis, Al[O(s-Bu)]3 was mixed with a solution of TEAOH in water and stirred at room temperature for 2 h. To this clear solution, a given amount of TEOS was added and stirred for an additional 2−3 h to enable its hydrolysis. The resulting aluminosilicate solution was heated at 80 °C for 3 h to remove the ethanol molecules generated by the hydrolysis of TEOS. Then, a solution of both TMACl and NaCl or of only TMACl or NaCl in water was slowly added with vigorous stirring to the CDM aluminosilicate solution prepared above. Also, an aluminosilicate synthesis solution with the composition 8.0TEAOH·1.0TMACl· 0.5Al2O3·8.0SiO2·240H2O was used to crystallize UZM-5 in the Na+-free system. The final synthesis solution was stirred at room temperature for 1 day, charged into Teflon-lined 23 mL autoclaves, and then heated under rotation (60 rpm) at 100−150 °C for a total period of 28 days. The solid products and mother liquors were separated by centrifugation (15000 rpm, 10 min). The recovered solids were redispersed in deionized water using an ultrasonic bath (100 W, 42 kHz) for 60 min and followed by centrifugation, which was repeated three times. Finally, the resulting solids were dried overnight at room temperature. For convenience sake, we will refer to the UZM-5 samples prepared in the presence and absence of a small amount of Na+ ions as Na-UZM-5 and UZM-5, respectively. Also, we will denote the UZM-9 sample prepared in the Na+-containing system as NaUZM-9. To demonstrate the effects of Na+ on breaking down the CDM barrier, a similar CDM aluminosilicate solution was treated with various amounts of aqueous NaCl to yield the series of compositions 8.0TEAOH·wNaCl·0.5Al2O3·8.0SiO2·240H2O with w = 1, 2, 4, and 8. These were prepared at room temperature using a high speed stirrer. To demonstrate the solution to gel transition with the NaCl treatment, a comparative aluminosilicate gel analogous to the w = 8 case with the composition 8.0NaOH·0.5Al2O3·8.0SiO2·240H2O was prepared by combining NaOH granules (99%, Aldrich), sodium aluminate (1.38Na 2 O·1.0Al 2 O 3 , Aldrich), and sodium silicate solution (0.77Na2O·1.0SiO2, Aldrich). To examine the evolution of the CDM barrier, a synthetic mother liquor, the composition of which

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RESULTS AND DISCUSSION Charge Density and Zeolite Synthesis. To illustrate the course of Na-UZM-5 and Na-UZM-9 syntheses, including the aspects of CDM zeolite synthesis like the CDM barrier, the effects of hydroxide level, and the cooperation of multiple SDAs, we first describe zeolite synthesis from a charge density perspective. These CDM syntheses start in the solution phase, and necessarily, solid formation requires the condensation of aluminosilicate anions. One may define a “global charge density” for the initial CDM synthesis mixture, by expressing the key components of the chemical composition, 8.0TEAOH· 8.0SiO 2 ·0.5Al 2 O 3 , in terms of the oxide formulation, TEA8Si8AlO21.5, taking account the hydroxide content via the relationship 2OH− ↔ O2− + H2O. Forgetting about the SDA for now, the initial aluminosilicate species, which is in reality a mixture of various aluminosilicate, silicate, and hydroxide 6686

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anions, may be globally characterized as [Si8AlO21.5]8−, where the charge density is −8 for 9 tetrahedral atoms (T atoms) or −0.89/T atom. Such a characterization is justified for these species related by quick equilibria. It should be noted that the “global charge density” calculated for the aluminosilicate solution in this manner is merely synonymous with the OH−/(Si + Al) or OH−/T atom ratio for the solution. Theoretically, the highest FWCD zeolitic solid possibly derived from the condensation of these anions would have Si/Al = 1 (according to Loewenstein’s rule), a framework formulation of [SiAlO4]−, with a charge density of −1 for 2 T atoms or −0.5/ T atom. Since the FWCD on the solid that forms must be lower than that of the starting solution, the charge density must increase for aluminosilicate species remaining in solution. Scheme 2 outlines this disproportionation in charge density, that of our “[Si8AlO21.5]8− species” to a lower FWCD zeolitic

Figure 2. Evolution of aluminosilicate solution charge density (charge/T atom) as a function of the fractional Al yield (y) and Si/ Al ratio (z) of isolated solids. The right vertical axis is an expanded scale for some of the curves, and the arrows indicate which scale to use.

Scheme 2. Disproportionation of the “Global” Aluminosilicate Synthesis Solution with an Oxide Formulation [Si8AlO21.5]8−, Which Was Used in Na-UZM-5 and Na-UZM-9 Syntheses, into Zeolitic Solid and Composite Aluminosilicate Solution Compositionsa

amount of Si converted to solid for selected Si/Al ratios (and corresponding FWCDs). All the curves start out at the charge density of −0.89/T atom associated with our starting synthesis mixture of oxide formulation [Si8AlO21.5]8− and increase with the extent of reaction in terms of the Al fraction converted to solid. The charge density increase is mild for the formation of Si/Al = 1 solids, because even as the fractional Al yield approaches 1.0, the poor fractional Si yield leaves the bulk of the T atoms in solution. At 90% conversion of Al (y = 0.9) to a zeolitic solid with Si/Al = 5.0, the charge density of the remaining synthesis mixture is more than double that of the initial CDM solution, while for a solid with Si/Al = 8.0, this rises to a factor of 9. Such an accumulation of solution charge density with condensation moves the synthesis mixture further away from the charge density of zeolites, leading to higher OH−/T atom ratios and small highly charged species, as illustrated for vanadate species in Scheme 1. Hence, the CDM barrier increases as the reaction proceeds, the accompanying evolution of more highly charged anions and the drift to higher charge density making further reaction more difficult. One way to drive the above-mentioned disproportionation required to produce a zeolitic solid is to attack the electrostatic TEA+-sustained CDM barrier with higher charge density alkali metal cations. Table 1 lists the oxide compositions, yields, and charge densities for the solids and solutions obtained by treating the CDM aluminosilicate solution with different amounts of NaCl at room temperature, yielding the series of compositions 8.0TEAOH·wNaCl·0.5Al2O3·8.0SiO2·240H2O with w = 1, 2, 4, and 8. Condensation of aluminosilicate anions increases as more Na+ is introduced, evidenced by an increase in fractional Al yield (y) from solution. At Na/Al = 1.0, which is theoretically enough to balance all the charges associated with Al atoms in an aluminosilicate network, y is only 0.047, and even less Si is recovered. Hence, most of the aluminosilicate species remain in solution. A Si/Al ratio of 2.21 indicates that Al is preferentially removed from solution, even though the initial concentration of Si is higher by a factor of 8. The driving force for condensation is the Coulombic stabilization associated with the formation of a highly charged network. The higher the charge density on the framework, the greater the Coulombic stabilization. Further addition of NaCl leads to a rapid increase in y to 0.25 at Na/Al = 2.0 and to >0.9 when Na/Al ≥ 4.0. Slight changes (2.21−2.67) in the Si/Al ratio are observed while increasing the Na/Al ratio from 1.0 to

a

A generalized version of this disproportionation for any hydroxidebased zeolite synthesis is given in Supporting Information Scheme S1.

solid and a higher charge density aluminosilicate solution. The disproportionation is characterized by parameters “y”, which is the fraction of Al converted to solid, and “z”, the Si/Al ratio of this solid. Both parameters are required to describe the extent of reaction to solid products and are also included in the description of the composition of the aluminosilicate solution product, the mother liquor, using mass and charge balance according to Scheme 2. In this illustration of the disproportionation, the cation/Al ratio in the solid is taken to be unity, which is often the case for the zeolitic solids isolated in this work, yielding a framework charge density for the solid, CDF, given by −1/(z + 1) in units of charge per T atom. To keep track of the disproportionation, it is not important if the solid is crystalline, amorphous, or both; only the composition matters. For the remaining aluminosilicate solution composition, the charge density, charge/T atom, is given by −(8 − y)/(9 − y(z + 1)). Since hydroxide is the source of charge in our system, we are essentially tracking its fate in the reaction, either as oxide ion incorporated into an aluminosilicate solid or as a solution species associated with alumino(silicate) anions or free hydroxide. Figure 2 shows plots of the evolution of the charge density, i.e., charge per T atom, for the remaining aluminosilicate solution, as a function of the extent of reaction, with the horizontal axis representing the fractional conversion of Al from solution to solid, y, and the different curves representing the 6687

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Table 1. Alkali-Induced Attack on the CDM Barrier: Oxide Compositions, Fractional Al Yields (y), Si/Al Ratios (z), and Charge Densities (CD) of Solid Products and CD of Solution Products Resulting from the Treatment of a CDM Aluminosilicate Solution with NaCl to Generate the Compositions 8.0TEAOH·wNaCl·0.5Al2O3·8.0SiO2·240H2Oa run

w (Na/Al)

oxide compositionb

y

z

solid CDCc

solution CD

1 2 3 4 5d

1.0 2.0 4.0 8.0 8.0

TEA0.050Na0.97Si2.21AlO6.43 TEA0.057Na1.13Si2.34AlO7.03 TEA0.046Na1.29Si2.47AlO7.11 TEA0.012Na1.37Si2.67AlO7.53 Na1.44Si2.60AlO7.42

0.047 0.254 0.921 0.919 0.932

2.21 2.34 2.47 2.67 2.60

−0.32 −0.36 −0.39 −0.38 −0.40

−0.90 −0.94 −1.17 −1.20 −1.18

a

All synthesis mixtures were prepared using Al[O(s-Bu)]3 and TEOS as Al and Si sources, respectively, unless otherwise stated, and treated at room temperature. bOxide stoichiometry was calculated to balance cation compositions. cCationic charge density, CDC, is used because cation/Al > 1 (See Supporting Information Scheme S1). dPrepared by combining NaOH, sodium aluminate, and sodium silicate.

out as a clear solution. The basic distinction between CDM and gel-type zeolite syntheses is that y, i.e., the fractional Al yield, starts out at 0 or very low in the former case. During the gel preparation, however, y is usually near unity for the entire zeolite crystallization process. This creates a very different dynamic for Al over the course of solid formation and crystallization. In the CDM synthesis, Al remains largely in solution and experiences the crystallization SDAs at roughly similar concentrations, which benefits cooperation between multiple SDAs. In the gel-type synthesis, Al has very limited solubility, and the small fraction in solution is overwhelmed in concentration by SDAs, a situation which cannot be beneficial to SDA cooperation. These different modes of synthesis and y value are controlled to a large extent by the SDA composition of the synthesis mixture. Comparison of Na-UZM-5 and Na-UZM-9 Syntheses. Figure 3 shows the powder XRD patterns of the solid products

8.0, the slight rise reflecting the concomitant Al depletion and Si enrichment in the solution. This suggests that the Si/Al ratio is mostly controlled by the ambient temperature and hydroxide level, as well as by the ability of Na+ to stabilize the charged aluminosilicate network. The extent of disproportionation can be estimated by looking at the charge densities of solid and solution products listed in Table 1. It should be noted that the cation/Al ratio is greater than unity in these materials, which indicates additional incorporation of hydroxide into the solid, perhaps due to trapped NaOH, terminal oxide ion, or defects. This must be accounted for to keep track of the disproportionation, so when excess cations are present in the solid, we use the cationic charge density, CDC, given by −(1 + c)/(z + 1), where c is the stoichiometric excess of cations with respect to Al (see Supporting Information Scheme S1). It is CDC that is compiled in Table 1 for the solid charge densities. After the addition of 1.0 or 2.0 equiv of Na+, the charge density of the solution has barely budged from the initial value of −0.89/T atom. Thus, the synthesis conditions have not been altered significantly. Increasing the Na+ addition to 4.0 equiv drives the charge density of the remaining aluminosilicate solution to −1.20/T atom, a 33% increase over the starting solution, and it is associated with the dramatic increase in Al yield (Si/Al = 72 in the solution when w = 4.0). No further changes in the charge density are caused by increasing the Na+ level to 8.0 equiv. These attacks on this CDM barrier with Na+ have resulted in a modest level of disproportionation like that shown in Figure 2 for low Si/Al ratio products. Table 1 also shows the compositional yield and charge density data for a “gel preparation” (run 5) with the corresponding synthesis mixture derived by mixing sodium silicate, sodium aluminate, and NaOH solutions with both Si/ Al and Na/Al (w) ratios of 8.0, but using the same amounts of water and hydroxide as those used in the preparation of the CDM aluminosilicate solution studied here. The Al fractional yield, Si/Al ratio, and charge density of the solution and solid products were found to be quite similar to those obtained from a CDM aluminosilicate solution with identical Si/Al and Na/Al ratios (run 4). Hence, it is possible to progress from a solution to a gel by controlling Na + addition to the CDM aluminosilicate solution. It is also apparent from the composition data that Na+ is preferentially incorporated into the solid, whereas very little TEA+ is incorporated. Because of this potency of Na+ in stabilizing networks of relatively high charge density, the conditions for CDM zeolite syntheses, where cooperation between multiple SDAs is generally desired, employ Na/Al ≤ 1.0 in order to prevent this dominance. For the CDM synthesis of Na-UZM-5 and Na-UZM-9 studied in this work, the synthesis mixture contains Na/Al = 0.5 and starts

Figure 3. Powder XRD patterns for a series of solid products obtained after Na-UZM-5 synthesis under rotation (60 rpm) at 150 °C.

separated after Na-UZM-5 synthesis as a function of time under rotation (60 rpm) at 150 °C. Two X-ray peaks around 2θ = 10.2 and 22.9° due to the (110) and (310) reflections of the UFI structure, respectively,37 began to be detectable after 1 day, and crystallization was almost complete after 3 days. The lack of (00l) reflections at the early stage of Na-UZM-5 synthesis, when the crystalline order was detectable by powder XRD, suggests that the growth rate of Na-UZM-5 crystals is considerably higher along the a and b axes than along the c axis. With prolonged heating, on the other hand, Na-UZM-5 was found to be less stable in the synthesis medium than NaUZM-9. After 1 week at 150 °C, an X-ray peak assignable to 6688

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zeolite beta was observed, and this large-pore zeolite became the major phase after 2 weeks, while after 2 weeks at 100 °C, Na-UZM-9 was the only product observed (Supporting Information Figure S1). The progress of the Na-UZM-5 and Na-UZM-9 syntheses is shown in Figure 4, which depicts the

Figure 4. Solid yields and relative crystallinities for the solid products obtained from the time series studies of Na-UZM-5 (left) and NaUZM-9 (right) syntheses under rotation (60 rpm) at 150 and 100 °C, respectively. The yield is given for the fraction of Si (■) and Al (●) converted to solid from solution, while the relative crystallinity (△) is also multiplied by the fractional yields to show the fraction of Si and Al residing in crystalline solids, denoted as Sixtal (□) and Alxtal (○), respectively.

Figure 5. A representation of the charge density disproportionations that occur upon addressing the CDM barrier (gray bar) during the synthesis of Na-UZM-5 and Na-UZM-9 at 150 and 100 °C, respectively. The disproportionations evolve with temperature and time. Specific points in this series of zeolite syntheses are labeled E0− E4 in order of increasing energy applied to the CDM barrier (in terms of temperature and time), along with the associated fractional Al yield (y). The circles depicting solid (●) and solution (○) species have areas proportional to the number of T atoms that have the indicated charge densities. During disproportion, all charges are conserved, and the solid and solution species balance on a lever arm about the initial charge density of the synthesis mixture. Further details can be found in Table 2.

amounts of both Si and Al that reside in solution, the solid state (the fractional Si and Al yields which includes both crystalline and amorphous solids), and in crystalline material in the solid state (derived from the crystallinity and the fractional yields). For both syntheses, it is easily seen that over the course of the synthesis, substantial portions of the Si and Al remain in solution, especially in the case of Na-UZM-9. For this reason, unlike a conventional zeolite gel synthesis, a crystallization curve is not an appropriate characterization of the progress of CDM reactions. While the former largely involves the transformation of an amorphous solid into a crystalline one, when crystallization begins in the Na-UZM-9 synthesis, over 90% of the Si and 80% of the Al are still in solution, so the major process is the conversion of solution species to solids. We note that 3 days of Na-UZM-5 synthesis at 150 °C gives the Si and Al fractional solid yields of 0.85 and 0.94, respectively, which are much higher than the values (0.30 and 0.70, respectively) observed after 9 days of Na-UZM-9 synthesis at 100 °C. Comparison of Na-UZM-5 and Na-UZM-9 syntheses provides a perfect opportunity to elucidate the influence of temperature on the CDM synthesis of zeolites, that is, how changes in the temperature alter the interactions with the CDM barrier and drive the disproportionation and SDA interactions that allow the formation of Na-UZM-5 and Na-UZM-9 at higher and lower temperatures, respectively. A charge density representation of the evolution of our CDM syntheses, which tracks the disproportionation to both solid and solution products while confronting the CDM barrier with different crystallization energies (temperature and time), is shown in Figure 5. The charge densities for zeolite solids were determined from elemental analysis while those for aluminosilicate solutions or mother liquors were calculated using the equations in Scheme 2, the fractional Al yield and the same zeolitic solid elemental analyses. For the solids from the 150 °C reactions, CDC is plotted in Figure 5 because of the excess

cation content over that of Al, while CDF is plotted for the solids from the 100 °C reactions. The starting point for zeolite synthesis, our aluminosilicate solution with the oxide formulation [Si8AlO21.5]8−, is labeled E0 and represented by the circle at a charge density of −0.89/T atom. The area of this circle is proportional to the total number of T atoms, 9. In the subsequent disproportionation reactions, all charges are conserved, and the circle area is proportional to the number of T atoms at the observed charge density, adding up to 9 for each disproportionation. The solid and solution products are thus related by the lever arm rule with respect to the initial charge density of the aluminosilicate synthesis solution. It is clear that the CDM barrier to zeolite synthesis in our system is significant, because of the high negative charge density (|−0.89|/T atom) of the initial synthesis mixture compared to the lower values ( 40 and TEA+/TMA+ > 26). In addition, the solution charge density has climbed to −1.23 from −0.89/T atom. These compositional developments, along with the higher charge developed on the aluminosilicate anions, serve to enhance the CDM barrier to condensation and eventually shut down the net progress of zeolite crystallization. This enhanced CDM barrier can be addressed as before by the addition of suitable crystallization inducing SDAs or sufficient heat. Heating the mother liquor isolated from fully crystallized Na-UZM-9 for an additional 7 days at 100 °C yielded no solids. The result is the same if half the amount of TMA+ used in the original synthesis is added to the mother liquor before the same digestion, while the use of Na+ instead of TMA+ produces more Na-UZM-9. To examine the effects of heat on the enhanced CDM barrier, a simulated Na-UZM-9 mother liquor, whose composition (25.9TEAOH·0.99TMACl· 0.64NaCl·0.5Al2O3·18.5SiO2·794H2O) is similar to that of the mother liquor of fully crystallized Na-UZM-9 isolated after 9 days at 100 °C, was prepared and heated at temperatures higher than 100 °C for various times. As shown in Supporting Information Figure S2, we were able to crystallize Na-UZM-9 after 3−6 days, a mixture of Na-UZM-5 and Na-UZM-9 after 14 days, and finally pure Na-UZM-5 after 28 days at 125 °C. When the same synthesis mixture was heated at higher than 150 °C, the solid yields were greater. However, the isolated phases were always amorphous. The top portion of Figure 5 shows the charge density disproportionations for the 150 °C synthesis products. Because these isolated solids contained excess cations, it was necessary to plot CDC in this figure, but not CDF, to attain the proper 6691

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production of solid via aluminosilicate anion condensation at 150 °C should have released more hydroxide than seen for the Na-UZM-9 reaction, yet the pH stayed near the starting value of 13.5, never approaching the 14.0 pH seen for Na-UZM-9. Apparently, the expected OH− release was offset by the OH− consumption of the decomposition. Since the charge density of the remaining aluminosilicate solution is thus smaller than the calculated value of −5.16/T atom, the reaction progressed further than it might have without the decomposition. This erosion of the CDM barrier may ultimately be responsible for the observed formation of zeolite beta with prolonged time, when the pH drops to 13 (Supporting Information Figure S1). The overall results described in Figure 5 demonstrate that the extent to which the disproportionation in charge density is driven depends on the severity of the reaction conditions to which the CDM barrier is exposed. The synthesis solution starts out at a charge density much higher than that of any zeolite. At lower temperatures, the attack on the barrier may become sufficient to give rise to the first accessible solids, low yields of amorphous aluminosilicates with higher charge densities that experience great Coulombic stabilization and whose formation mainly relies on the incorporation of crystallization SDAs. Likewise, at higher temperatures, a more vigorous attack on the barrier drives the disproportionation in charge density further, giving higher yields of lower charge density, less Coulombically stabilized amorphous networks that readily incorporate more CDM SDA like TEA+ along with the crystallization SDAs. In each case, the solid formation slows and the CDM barrier re-establishes itself as solution charge density (i.e., OH−/T atom) levels increase and crystallization SDA levels are reduced. At this stage, the mixed SDA-containing amorphous solids are in contact with an aluminosilicate solution that contains the bulk of the T atoms and crystallization SDAs; all species are accessible. It is in this environment that a nucleation event occurs and crystallization begins, providing a new driving force for further solid formation, in this case, Na-UZM-9 at 100 °C and Na-UZM-5 at 150 °C. The presence of the flexible CDM barrier, the temperature dependent incorporation of ubiquitous TEA+, and the low concentrations of the dominant crystallization SDAs creates an adaptable synthesis system that enables cooperation between multiple SDAs during zeolite synthesis under a variety of conditions. In fact, a gradual increase in synthesis temperature from 100 to 150 °C resulted in the dramatic change from Na-UZM-9 to Na-UZM-5 to zeolite beta (Supporting Information Figure S1). The SEM images of fully crystallized Na-UZM-5 and UZM-5 can be found in Supporting Information Figure S4. Both zeolites typically appear as very thin plates with less than 100 nm in thickness.20,27,30 However, the crystallite size is much bigger for Na-UZM-5, which should be associated with the presence of Na+ in its synthesis mixture. To more precisely examine the role of this alkali cation in the crystal growth process of UFI-type zeolites, we separated a series of solid products as a function of time during UZM-5 synthesis in the Na+-free system and compared their powder XRD patterns. As can be shown in Supporting Information Figure S5, the X-ray peaks around 2θ = 10.2 and 22.9°, corresponding to the (110) and (310) reflections of the UFI structure, respectively,37 are detectable after 12 h of heating at 150 °C. Fully crystallized UZM-5 can be obtained after ca. 4 days, with fractional Si and Al yields of 0.71 and 0.79, respectively, which are somewhat smaller than the values (0.85 and 0.94, respectively) observed

(Figure 5 and Table 2). Meanwhile, the FWCD of the product solids decreases from −0.15 (Si/Al = 5.59) to −0.13/T atom (Si/Al = 6.61), representing an 18% Si enrichment. This reaction has passed from the initial tendency to form Coulombically stabilized high charge density amorphous networks from solution to the assembly of the crystalline composition, which comes from both the amorphous solid and the solution. In fact, the fractional Na+ yield decreases from 0.39 to 0.26 between 1 and 2 days, suggesting the dissolution of the initially formed amorphous solids and their subsequent recrystallization (Table 2). During the final approach to the fully crystallized Na-UZM-5, the period between 2 and 3 days, there is virtually no change in the Al fractional yield. However, the fractional Si yield increases from 0.79 to 0.85. We also note that the FWCD decreases from −0.13 (Si/Al = 6.61) to −0.12/T atom (Si/Al = 7.13), while Alxtal increases from 0.74 to 0.94 for the zeolite product (Figure 4). These developments indicate that the remaining higher charge density amorphous solid initially formed has dissolved and recrystallized with the lower FWCD crystallization composition, extracting more Si from solution in the process, which can be further supported by the decline in the fractional Na+ yield from 0.26 to 0.21 that accompanies the dissolution of the amorphous solid (Table 2). The TEA+−TMA+−Na+ combination of SDAs effectively accommodates the transition to lower FWCD solid products as the reaction proceeds from E3 (12 h) to E4 (3 days). During this period, the incorporation of low charge density TEA+ becomes more favorable. However, that of high charge density Na+ becomes less favorable since the TEA+/Al ratio increases from 0.29 to 0.48 and the Na+/Al ratio decreases from 0.36 to 0.11 (Supporting Information Table S1). The fractional Na+ yield peaks at 1 day (0.39) before about half is released back into solution by the end of the synthesis (Table 2). By contrast, Na-UZM-9 synthesis shows a similar decrease in Na+/Al ratio with the decreasing charge density of the solid products, but the Na+ yield steadily increases over the entire reaction. There is substantial incorporation of TMA+ over the entire process of Na-UZM-5 synthesis as the TMA+/Al ratio increases from 0.41 to 0.55. As shown in Table 2, the fractional TMA+ yield is about 1.0 after 3 days, so it may be considered a limiting reagent. After 3 days, the fractional Si and Al yields in the isolated solid are 0.85 and 0.94, respectively, and the Si/Al ratio of the remaining solution is about 21.8. An additional 2 days of heating at 150 °C slightly increases the fractional Si yield to 0.87. Unlike Na-UZM-9 synthesis, the crystallization of NaUZM-5 is nearly complete, suggesting that 150 °C is a very effective condition for attacking this CDM barrier. We should note here that the calculated charge density of the remaining aluminosilicate solution is −5.16/T atom, which is ca. 6 times higher than that (−0.89/T atom) of the initial synthesis solution. This value suggests a formidable barrier to solid formation, because it is so far away from the FWCD of any zeolite (Figure 5), indicating an OH−/T atom ratio >5 for the aluminosilicate solution. In fact, the CDM barrier is lowered during the course of the reaction due to the decomposition of TEA+ (NEt4+) to triethylamine (NEt3), which is clearly evidenced by 13C NMR analysis of mother liquors (Supporting Information Figure S3). The Hofmann elimination consumes hydroxide via the reaction NEt4+ + OH− → NEt3 + C2H4 + H2O, eroding the CDM barrier by lowering the charge density of the aluminosilicate solution. This process is supported by the pH measured for the Na-UZM-5 mother liquors. The superior 6692

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in Na-UZM-5 synthesis. It is remarkable that after 1 day, the fractional Al yield is already 0.76, nearly the value seen at 4 days for the fully crystallized UZM-5. In the period between 1 and 4 days, mostly higher charge density amorphous product is redissolved and crystallized in a more Si-rich composition as Alxtal increases from ca. 0.25 to 0.75, while the Si fractional yield increases mildly from 0.60 to 0.71 (Supporting Information Figure S5). When the reciprocal of the induction times to give 0.05 fractional crystallinity and the slope of crystallization curves at 0.50 fractional crystallinity in Figure 4 and Supporting Information Figure S5 were taken as relative nucleation and crystal growth rates for the synthesis of Na-UZM-5 and UZM5, respectively,20,38−40 the nucleation rate of the former zeolite was calculated to be approximately half the value of the latter one. As shown in Table 3, however, the relative crystal growth

induction time,a h

nucleation rateb

crystal growth ratec

Na-UZM-5 UZM-5

24 11

1.0 2.2

12.0 1.0

CONCLUSIONS

A charge density model of zeolite synthesis is presented and illustrated with the CDM synthesis of Na-UZM-5 and NaUZM-9 at 150 and 100 °C, respectively, in the TEA+−TMA+− Na+ mixed-SDA system. The model assigns a global charge density to the initial synthesis solution, taking into account both the aluminosilicate composition and the hydroxide content with all species expressed as oxides and the charge density expressed in terms of charge/T atom. The synthesis proceeds as a temperature-driven disproportionation of the original synthesis mixture to solution and solid products with diverging charge densities, a lower charge density solid and a higher charge density aluminosilicate solution. The CDM barrier to condensation/crystallization is described in terms of the charge density mismatch between the CDM SDA (TEA+) and the FWCD of possible products, but also in terms of the hydroxide component, which establishes the difference in charge density between the aluminosilicate solution and possible target zeolite products. Solid formation and zeolite crystallization from the aluminosilicate solution synthesis mixture are induced by attacking the CDM barrier with crystallization SDAs (Na+ and TMA+) and heat. The driving force for solid formation is the Coulombic stabilization associated with a charged aluminosilicate framework. In Na-UZM-9 synthesis at 100 °C, the charge density disproportionation proceeds to a small extent, forming a small amount of a high FWCD solid (−0.29/T atom, Si/Al = 2.48), in which the high charge density crystallization SDAs (Na+ and TMA+) are mainly incorporated. Solid formation tapers off slightly with time as the CDM barrier re-establishes itself, but picks up again after 1 day when crystallization begins, which provides an additional driving force for solid formation from solution. In Na-UZM-5 synthesis at 150 °C, the charge density disproportionation is driven to a greater extent, forming much lower FWCD solid (−0.16/T atom, Si/Al = 5.45) that incorporates the CDM SDA TEA+ in addition to the crystallization SDAs. As with the Na-UZM-9 synthesis, initial solid formation slows and nucleation occurs after 1 day, when crystallization begins to drive further solid formation. In each case, nucleation occurs in the presence of a solid containing multiple SDAs and an aluminosilicate solution containing the bulk of the T atoms and all of the SDAs. Conducting zeolite synthesis with the CDM barrier opposing the Coulombic stabilization of solid formation allows temperature controlled management of the charge density disproportionation, including selectively precipitating solids of a desired charge density and controlling which SDAs are incorporated, while most keep most T atoms and SDAs in solution, an excellent environment for nucleating zeolites that engage in SDA cooperation. The charge density model of zeolite synthesis presented here can be a useful tool for the design and mapping of zeolite syntheses. Consideration of simple high level charge density principles, including motivation for solid formation (Coulombic stabilization and its temperature dependence), provision of pathways to solid formation (concentration and charge density of crystallization SDAs), and aluminosilicate solution solubility (CDM SDA and aluminosilicate solution charge densities and associated barrier), one can design fairly complex reactions with some expectation of control over the final composition.

Table 3. Relative Rates of Nucleation and Crystal Growth for the Synthesis of Na-UZM-5 and UZM-5 under Rotation (60 rpm) at 150 °C, with and without a Small Amount of Na+ Ions Present, Respectively zeolite

Article

a

Required to reach 0.05 crystalline fraction. bProportional to the reciprocal of induction time. cProportional to the slope of crystallization curves at 0.50 crystalline fraction.

rate of Na-UZM-5 is over 10 times faster than that of UZM-5. These results can be clearly rationalized from a charge density point of view and provide an opportunity to compare efficacy of Na+ and TMA+ as crystallization SDAs. In Na-UZM-5 synthesis, high charge density Na+ ions efficiently promote the condensation of charged aluminosilicate solids from solution. This may lead to a faster crystal growth rate and larger crystals than can be obtained in the Na+-free UZM-5 synthesis medium. The presence of the higher charge density Na+ ion also allows the stabilization of a rather higher FWCD product (−0.16/T atom; Si/Al = 5.45) after 12 h in the NaUZM-5 synthesis medium; the same period of heating in the Na+-free UZM-5 synthesis results in the formation of a solid product with FWCD = −0.14/T atom (Si/Al = 6.12). Both products are amorphous at this stage and have to be transformed to form UZM-5 crystals. The Na+-free UZM-5 product has a FWCD and composition much closer to that of the ultimate UZM-5 crystallization composition (FWCD = −0.12/T atom, Si/Al = 7.1), which may make the formation of UZM-5 nuclei more accessible than for the early Na-UZM-5 compositions. The importance of TMA+ in Na-UZM-5 crystallization can be found in Table 2 as the fractional TMA+ and Al yields closely mirror each other. This suggests that UZM-5 nucleation should be more facile in the Na+-free UZM-5 synthesis medium because of the increased TMA+ content (TMA+/Al = 1) over that (TMA+/Al = 0.5) of the NaUZM-5 synthesis mixture. When we tried to synthesize UZM-5 using an aluminosilicate solution with the same hydroxide level as that of the synthesis solution described above, but without Na+ present and thus with a higher TEA+/TMA+ ratio (16 vs 8), in fact, we were not able to obtain fully crystallized UZM-5 even after 2 weeks of heating at 150 °C. This implies that there is a minimum concentration of crystallization SDAs required to complete zeolite synthesis at these CDM conditions. 6693

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(12) Zones, S. I. U.S. Patent 4,483,835, 1984. (13) Davis, M. E.; Zones, S. I. In Synthesis of Porous Materials; Occelli, M. L., Kessler, H., Eds.; Marcel Dekker: New York, 1997; p 1. (14) Camblor, M. A.; Hong, S. B. In Porous Materials; Bruce, D. W., O’Hare, D., Walton, R. I., Eds.; Wiley: Chichester, 2010; p 265. (15) Moliner, M.; Rey, F.; Corma, A. Angew. Chem., Int. Ed. 2013, 52, 2. (16) Lewis, G. J.; Miller, M. A.; Moscoso, J. G.; Wilson, B. A. U.S. Patent 7,578,993, 2009. (17) 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. (18) Miller, M. A.; Moscoso, J. G.; Koster, S. C.; Gatter, M. G.; Lewis, G. J. Stud. Surf. Sci. Catal. 2007, 170A, 347. (19) Miller, M. A.; Lewis, G. J.; Moscoso, J. G.; Koster, S.; Modica, F.; Gatter, M. G.; Nemeth, L. T. Stud. Surf. Sci. Catal. 2007, 170A, 487. (20) Kim, S. H.; Park, M. B.; Min, H.-K.; Hong, S. B. Microporous Mesoporous Mater. 2009, 123, 160. (21) Lee, J. H.; Park, M. B.; Lee, J. K.; Min, H.-K.; Song, M. K.; Hong, S. B. J. Am. Chem. Soc. 2010, 132, 12971. (22) Park, M. B.; Cho, S. J.; Hong, S. B. J. Am. Chem. Soc. 2011, 133, 1917. (23) 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. (24) Pope, M. T. Heteropoly and Isopoly Oxometalates, Inorganic Chemistry Concepts Vol. 8; Springer-Verlag: Berlin, Heidelberg, 1983; p 35. (25) Mortlock, R. F.; Bell, A. T.; Radke, C. J. J. Phys. Chem. 1991, 95, 372. (26) Moscoso, J. G.; Lewis, G. J.; Gisselquist, J. L.; Miller, M. A.; Rohde, L. M. U.S. Patent 6,713,041, 2004. (27) Blackwell, C. S.; Broach, R.; Gatter, M. G.; Holmgren, J. S.; Jan, D. Y.; Lewis, G. J.; Mezza, B. J.; Messa, T. M.; Miller, M. A.; Moscoso, J. G.; Patton, R. L.; Rohde, L. M.; Schoonover, M. W.; Sinkler, W.; Wilson, B. A.; Wilson, S. T. Angew. Chem., Int. Ed. 2003, 42, 1737. (28) Moscoso, J. G.; Lewis, G. J.; Miller, M. A.; Jan, D.-Y.; Patton, R. L.; Rohde, L. M. U.S. Patent 6,613,302, 2003. (29) Broach, R. W.; Sinkler, W.; Patton, R. L.; Mezza, T. M.; Gatter, M. G. Stud. Surf. Sci. Catal. 2004, 154, 1188. (30) Gatter, M. G. Stud. Surf. Sci. Catal. 2004, 154, 1324. (31) Jan, D. Y.; Lewis, G. J.; Mezza, T. M.; Moscoso, J. G.; Patton, R. L.; Koljack, M. P.; Tota, P. V. Stud. Surf. Sci. Catal. 2004, 154, 1332. (32) Bellussi, G.; Carati, A.; Rizzo, C.; Millini, R. Catal. Sci. Technol. 2013, 3, 833. (33) Sastre, G.; Leiva, S.; Sabater, M. J.; Gimenez, I.; Rey, F.; Valencia, S.; Corma, A. J. Phys. Chem. B 2003, 107, 5432. (34) Cho, H. H.; Kim, S. H.; Kim, Y. G.; Kim, Y. C.; Koller, H.; Camblor, M. A.; Hong, S. B. Chem. Mater. 2000, 12, 2292. (35) Gies, H.; Marler, B. Zeolites 1992, 12, 42. (36) Feoktistova, N. N.; Zhdanov, S. P.; Lutz, W.; Bülow, M. Zeolites 1989, 9, 136. (37) Baerlocher, Ch.; McCusker, L. B. Database of Zeolite Structures. http://www.iza-structure.org/databases/. (38) Cundy, C. S.; Cox, P. A. Microporous Mesoporous Mater. 2005, 82, 1. (39) Serrano, D. P.; Uguina, M. A.; Sanz, R.; Castillo, E.; Rodriguez, A.; Sanchez, P. Microporous Mesoporous Mater. 2004, 69, 197. (40) Jhung, S. H.; Jin, T.; Hwang, Y. K.; Chang, J. S. Chem. Eur. J. 2007, 13, 4410.

ASSOCIATED CONTENT

S Supporting Information *

Table S1: Chemical composition data for the series of solids isolated during Na-UZM-5 synthesis at 150 °C as a function of time. Table S2: Chemical composition data for the series of solids isolated during UZM-5 synthesis at 150 °C as a function of time. Scheme S1: Disproportionation in charge density of a general aluminosilicate solution with an oxide formulation [SixAlO(2x+1.5+n/2)]n− in a hydroxide-based zeolite synthesis. Figure S1: Powder XRD patterns of the solid products obtained after heating an aluminosilicate synthesis solution with the composition 8.0TEAOH·0.5TMACl·0.5NaCl·0.5Al 2 O 3 · 8.0SiO2·240H2O at different temperatures. Figure S2: Powder XRD patterns of the solid products obtained after heating a simulated Na-UZM-9 mother liquor at 125 °C as a function of time. Figure S3: Solution 13C NMR spectra of a series of mother liquors separated after Na-UZM-5 synthesis under rotation (60 rpm) at 150 °C for different times. Figure S4: SEM images of as-made (a) Na-UZM-5 and (b) UZM-5 prepared in the TEA+−TMA+ mixed-organic SDA system. Figure S5: Powder XRD patterns, fractional Si and Al yields, relative crystallinities and fractional yields of Si and Al residing in crystalline material for a series of solid products obtained after UZM-5 synthesis under rotation (60 rpm) at 150 °C for different times. This material is available free of charge via the Internet at http://pubs.acs.org.

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AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected]. *E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by UOP LLC and the National Creative Research Initiative (2012R1A3A2048833) and BK 21plus programs through the National Research Foundation of Korea funded by the Korea government (MSIP).

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DEDICATION Dedicated to Edith Flanigen on the occasion of receiving the U.S. National Medal of Technology and Innovation. REFERENCES

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