High aluminum content Beta zeolite as an active Lewis acid catalyst

Subscriber access provided by ALBRIGHT COLLEGE

Kinetics, Catalysis, and Reaction Engineering

High aluminum content Beta zeolite as an active Lewis acid catalyst for #-Valerolactone decarboxylation Xue Wang, Jing Zeng, Xingmei Lu, Jiayu Xin, and Suojiang Zhang Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.9b01604 • Publication Date (Web): 05 Jun 2019 Downloaded from http://pubs.acs.org on June 11, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Industrial & Engineering Chemistry Research

High aluminum content Beta zeolite as an active Lewis acid catalyst for γ-Valerolactone decarboxylation Xue Wanga, b, Jing Zenga, Xingmei Lub, c, Jiayu Xinb, c*, Suojiang Zhangb, c* a. School of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang, 110034, P. R. China. b. Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China c. School of Chemical and Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China *Corresponding author: E-mail: [email protected] [email protected]

1

ACS Paragon Plus Environment

Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Abstract: Butene play essential role in the area of petrochemical industry. The production of butene from biomass-derived platform molecule γ-valerolactone (GVL) is of great interest recently. While, GVL decarboxylation reaction occurred under high temperature since the catalytic activity of the catalysts used before was not efficient for this reaction. In this work, beta zeolite with Si:Al=5 was synthesized and used for GVL decarboxylation. It exhibited a higher catalytic performance than other commercial zeolites due to a large number of Lewis acid sites and relatively large micropore size. At 300℃, 99.5% GVL conversion and 98% butene yield were obtained after condition optimizing. For further research, the influence of Brønsted/Lewis acid ratio was investigated, and it turned out that Lewis acid was more active than Brønsted acid in crystalline material on GVL decarboxylation for the first time. Keywords ：γ-valerolactone, Lewis acid, Zeolite Beta, Decarboxylation, butene

1.Introduction To face the fossil fuel resources crisis, it is necessary to develop new processes for the production of fuels and chemicals

1-4.

Producing fuels from biomass have attracted wide

attention 6-12 due to their extensive sources and low cost 13. There are many strategies between the conversion biomass into fuels, including biomass pyrolysis, gasification thermal liquefaction

35.

However, these processes have some drawbacks, such as low conversion

efficiencies or long treatment times. Recently, the synthesis of fuels by conversion of platform chemicals obtained by biomass is the most widely approach29,36. In this respect, γ-valerolactone (GVL) is one of the most potential platform molecules for production chemicals 14, which can be produced directly through hydrogenation of levulinic acid 15,16 that conversion from C6 or C5 sugars in lignocellulosic biomass 17.

2


Page 2 of 25

Page 3 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Generally, an important application of GVL is to produce butene by decarboxylation reaction over solid acids. GVL decarboxylation reaction was occurred under harsh conditions (e.g., 350°C or high pressure) due to the low activity of the catalysts used before. A number of materials have been used for catalyzing GVL decarboxylation reaction, including ZSM-5 zeolites 21, ASA (amorphous silica-alumina) 18-21,23, γ-Al2O3 20,21,24 and supported catalysts 20,21. Among these samples, the high Al ZSM-5 sample (H-ZSM-5-30) was the most active sample for GVL decarboxylation reaction due to their abundant Brønsted acid sites and intrinsic activity of crystalline materials 21. Even though many kinds of solid acids have been used for GVL decarboxylation, Lewis acid zeolites used for this reaction has not been reported 18-24. Beta zeolites, with a three-dimensional 12-membered ring pore structure (0.64 nm × 0.76 nm in two directions and 0.55 nm × 0.55 nm in the third direction), as well as abundant Lewis acid sites, has been reported as excellent catalysts for industrial fields and biomass catalytic conversion, including fluid bed catalytic cracking (FCC) 25 and methanol to olefins (MTO) 26 and the production of platform molecules 27,28. Moreover, the Lewis acid sites in beta zeolites can catalyze epoxide ring open efficiently 34. So, beta zeolite is a promising material on GVL decarboxylation. Here, high aluminum content (Si/Al =5) beta zeolite was synthesized and firstly employed as catalysts in GVL decarboxylation reaction. According to the experiment result, beta zeolites was the most active sample tested here. To the best of our knowledge, it is the first time to turned out that Lewis acids were more active than Brønsted acids for GVL decarboxylation reaction. By analyzing the physicochemical properties of all samples (beta, HY-5.3, H-ZSM5, γ-Al2O3) used here and their catalytic performance on GVL decarboxylation, it is discovered that the butene yield was proportional to the amount of Lewis acid sites when the effect of physical properties was eliminated. Furthermore, the pore size of beta zeolites (0.62nm) was

3



larger than the kinetic diameter of GVL (0.5-0.6nm), which reduced diffusion limitations of GVL in beta zeolites’ pore and eventually enhanced butene yield greatly.

2. Materials and methods 2.1. Materials Sodium aluminate(NaAlO2, >98%, Sinopharm Chemical Regent Co. Ltd), Sodium hydroxide (NaOH, AR, Xilong Scientific Co .Ltd), Fumed silica(AR , Macklin Biochemical Co. Ltd ), γ-Valerolactone (GVL, >98%, Shanghai Aladdin biochemical technology Co. Ltd), H-ZSM-5-38(Nankai University Catalyst Co. Ltd), H-ZSM-5-200 (Nankai University Catalyst Co. Ltd), H-Y-5.3(Nankai University Catalyst Co. Ltd), H-beta-25(Nankai University Catalyst Co. Ltd), H-beta-62(Nankai University Catalyst Co. Ltd) γ-Al2O3 (Shanghai Aladdin biochemical technology Co. Ltd). Ultra-pure water and distilled deionized water (Laboratory self-made). 2.2. Catalyst preparation High Al beta zeolites were synthesized by adding Commercial H-beta-25 zeolite beta (Nankai University Catalyst Co. Ltd) as seeds (Si/Al=25) to Na+-aluminosilicate gels with molar composition: 0.2Na2O: 0.04Al2O3: 1.0SiO2: 20H2O. The preparation procedure is as follows: sodium aluminate and sodium hydroxide were dissolved in ultra-pure water to obtain a clear solution. Then, fumed silica and Beta seeds (1wt% of silica source) were slowly and successively added to the clear solution. A homogeneous aluminosilicate gel was obtained after stirred. Aluminosilicate gel was transferred to a 100 ml stainless-steel autoclave and was then subjected to hydrothermal treatment at 140℃ for 72 h in an oven under autogenous pressure. Then the product was filtered, washed thoroughly with distilled water, dried at 80℃ and calcined at 450℃ for 5h.

4


Page 4 of 25

Page 5 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Commercial samples: all commercial samples with different Si to Al ratios (H-ZSM-5-38, H-ZSM-5-200, H-Y-5.3, H-beta-25, H-beta-62, γ-Al2O3) were calcined in muffle furnace prior to use (3K/min, 773 K, 5 h). 2.3. Catalyst characterization X-ray diffraction (XRD) patterns were recorded on an X-ray diffractometer (Bruker/D8 Focus diffractometer) using Cu Kα radiation at 40kV and 40mA. The catalyst morphologies were observed by the SEM (field-emission scanning electron microscopy, JEM-6100F, JEOL Japan). The porous structure of the samples was investigated by N2 sorption at −196°C (Micromeritics ASAP 2460). Prior to analysis, all samples were degassed under vacuum at 350°C for 4h. The specific surface areas were determined by the Brunauer-Emmett-Teller (BET) method in the relative pressure (p/p0) range of 0 to 1. Surface acidity density was determined using a Micromeritics AutoChem II instrument by NH3 temperature programmed desorption (NH3-TPD) loaded with 0.05 g sample. In a typical NH3-TPD experiment, sample was pretreated in He flow at 500°C for 60 min, and cooled to 100°C. Then the flow was switched to 10%NH3/He (25mL min−1) and kept for 60 min followed by He (25mL min−1) sweeping for 60 min. Finally, the sample was heated in He flow (25 mL min−1) to 700°C at a rate of 10°C min−1. In addition, the surface basicity density was measured by CO2-TPD with the similar conditions. Relative quantities of Brønsted and Lewis sites were measured by adsorbing of pyridine on catalyst samples using in situ infrared spectroscopy (Nicolet 6700) equipped with vacuum system. In a typical pyridine adsorption experiment, samples were pressed into self-supporting wafers(10-15mg) and were calcined in vacuum for 2h at 500°C.Then, the samples were cooled to 100°C and collect backgrounds at several different temperatures by temperature programming. After that, the samples were cooled to 30°C and adsorbed pyridine for 30min in the condition of the in-situ vacuum valve closed. Then, open the in-situ vacuum valve and hold 5



on 30 min (100°C) to remove physically adsorbed pyridine. At last, infrared spectrum of pyridine desorption curve were collected at several different temperatures with temperature programming. Brønsted and Lewis site were quantified using the equations reported by Emeis et al 32. Here, we employed molar extinction coefficients, which are 1.88 and 1.42 cm μmol−1 for Brønsted and Lewis sites, respectively. 2.4. Catalytic activity testing Batch reaction for GVL decarboxylation was carried out in a 50ml stainless-steel autoclave (Hai An Petroleum Scientific Instruments Co. Ltd) with a gas pressure gage. First, GVL and catalyst were added into the reactor, followed by filling with nitrogen. Then the stainless-steel autoclave was heated to the target temperature by electric furnace (Hai An Petroleum Scientific Instruments Co. Ltd) for different reaction time. Reaction temperature was monitored using a thermocouple positioned against the center of the reactor, and temperature was regulated using a PID controller (Ningbo Hengli Instrument Co. Ltd). After the reaction, the reactor was immediately cooled down with tap water. All gas products (butene isomers, CO2) was collected into reservoir bag and quantified by GC-MS (GCMS-QP2020, SHIMADZU; a Rtx-5MS capillary column, Agilent) through a Manual GC Syringes (Shanghai anting micros ampler factory). The all remained liquid products was dissolved in ethyl alcohol and quantified by GCFID (GC-2014, SHIMADZU; a Rtx-5MS capillary column, Agilent) and GC-MS through an automatic liquid injector for GC (AOC-20i, SHIMADZU.) 3. Results and discussion Since the GVL decarboxylation was influenced by multiple factors, including the type of catalysts, acid strength, acid density, as well as physical properties. Therefore, catalysts were characterized by different kinds of methods. The catalytic performance of catalysts and their physicochemical properties will be discussed below. 3.1. Structural and textural properties 6


Page 6 of 25

Page 7 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure.S1 shows the XRD patterns of all samples. As shown in the Figure.S1, all samples have their typical diffraction peaks, with high crystallinity and a negligible impurity phase. Figure.S2 displays the SEM images of Na-beta-5 samples. The beta particles are approximately sphere-shaped with diameters in the range of 200-500 nm. The EDS spectrum in Figure.S3 shows that the Na-beta-5 contains elements of Si, Al, O and Na. The surface content of Si and Al detected by EDS were 27.29wt% and 5.59wt% respectively (Si/Al=5:1). The N2 adsorption-desorption isotherms at low temperature of samples are showed in Figure.S4. An H4 -type hysteresis loop appears obviously for H-Y-5.3, Na-beta-5 and H-beta25 sample. The large hysteresis loop suggests that the pore diameter distribution is relatively wide. The other samples have no obvious large hysteresis loop. The BET surface area and pore diameter of the samples are listed in Table 1. 3.2. Acid and base properties The results of surface acidity and basicity of samples were measured by NH3-TPD, and the results are given in Figure.S5. Na-beta-5 and H-Y-5.3 has only one peak in about 200°C correspond to the weak acid sites. H-beta-25 and H-ZSM-5-38 have two peaks in around 200°C and 400°C correspond to weak and medium acid sites respectively (Figure.S5). H-beta-62 also have two peaks in 300°C and 400°C correspond to weak and medium acid sites respectively. For H-ZSM-5-200 and γ-Al2O3, there were small peaks in 300°C and 600°C respectively (Figure.S5). Interestingly, the beta samples have corresponding acidity and basicity, suggesting that the beta sample which has strong acid sites meanwhile has strong base sites (Figure.S5). It can be seen from the Figure.S5 that the base sites of the other catalysts were weak base sites with lower base densities. The weak base sites have less effect on the acid catalyzed reaction compare to strong base sites. Besides, the number of acid sites or base sites was listed in Table S1.

7



Page 8 of 25

The Brønsted and Lewis sites were measured by Pyridine-IR, and the results are given in Figure.S6. In the pyridine-IR spectra, the bands at 1450cm-1 and 1540cm-1 are attributed to Lewis acidic sites and Brønsted acidic sites, respectively. The band at 1490 cm -1 corresponds to both Brønsted acidic sites and Lewis acidic sites. As can be seen from Figure.S6, beta samples and γ-Al2O3 are typical Lewis acid catalysts. For H-ZSM-5 and H-Y-5.3 samples, they are typical Brønsted acid catalysts. The densities of B acid and L acid were list in Table 1. The physical and chemical properties of all samples were summarized in Table 1. It mainly lists BET surface area, pore size, Brønsted acid and Lewis acid densities. Besides, the butene yield of GVL decarboxylation reaction was also be listed in Table 1. Further discussion will be shown later in this literature. Table 1 Summary of physicochemical properties and comparison of catalytic activities of samples considered.

BET surface

Average pore

B acids

L acids

area (m2g −1)

diameter /nm

((μmol g −1)a

((μmol g −1)a

410

0.53

103

4.90

21

35

365

0.56

33

1.90

17.3

30

H-beta-25

548

0.62

21.0

124

0.17

67

H-beta-62

456

0.61

0.71

71.0

0.01

37

H-Y-5.3

641

0.74

72.0

11.0

6.6

56

γ-Al2O3

178

3.3

0

21.0

0

23

553

0.62

37.0

187

0.2

90

Catalyst

HZSM-5 -38 HZSM-5 200

Na-beta5

B/L ratiosa

Butene Yield

Reaction conditions: GVL (1g), solid acid(0.1g), N2(2MPa),300°C, 4.5h. a. Calculated by the pyridine FT-IR spectra(300°C) according to the formula reported by Emeis et al. 32.

3.3. Catalytic conversion of GVL into butene by various solid acid catalysts

8


（%）

Page 9 of 25

Several solid acids were used for catalyzing GVL decarboxylation at different temperature and the results are summarized in Figure.1. The H-ZSM-5 zeolites have been reported as excellent catalysts for GVL decarboxylation 21. Therefore, they were employed as catalysts in this reaction as a contrast. The results show that the GVL decarboxylation reaction is extremely sensitive to reaction temperature. Higher reaction temperature lead to higher GVL conversion and butene yield for all samples tested. Obviously, beta zeolite is the most active catalyst of the samples tested here on average. H-Y-5.3 zeolite is less active than beta zeolite and more active than H-ZSM-5 zeolite. The only non-zeolite sample γ-Al2O3 was the most inactive one. The order of catalytic activity for H-ZSM-5-38, H-ZSM-5-200 and γ-Al2O3 was consistent with the previous report 21. Further discussion of physicochemical properties and their impact on

200

100

180

80

160

60

140

40

120 100 80 60

20 γ-Al2O3 HZSM-5-200 HZSM-5-38 Hbeta-62 HY-5.3 Hbeta-25 Nabeta-5

0

GVL Conversion /%

catalytic activity will be showed in the subsequent sections.

Butene Yield /%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


-20 -40

40

-60

20

-80

0

-100 260

280

300

320

340

Temperature /℃

Figure.1. The results of GVL decarboxylation reaction with several solid acids as catalysts at different temperature. Reaction conditions: GVL (1g), solid acid(0.1g), N2(2MPa), reaction time(4.5h).

According to the data listed in Table 1 and Figure.1, it can be observed that Na-beta-5 and H-beta-25 were the top two efficient catalysts with the most butene yields under the same conditions due to their highest Lewis acid sites of 187μmol g −1 and 124μmol g −1, respectively. 9



Page 10 of 25

On the contrary, the butene yields were the lowest using H-ZSM-5-38 and H-ZSM-5-200 which have the least Lewis acid sites of 4.90μmol g

−1

and 1.90μmol g

−1.

The H-Y-5.3

exhibited a slightly secondary performance with intermediate Lewis acid sites of 11.0μmol g −1.

However, the catalytic performance of H-beta-62 was so poor with as high as 71μmol g −1

Lewis acid sites. For further explore, CO2-TPD was examined to measure the basic sites of the beta samples. Results shows that, H-beta-62 not only had strong acid sites but also had lots of strong basic sites. For acid-catalyzed reaction, it is disadvantaged to have so many strong basic sites in the catalyst. So, it can be supposed that the low catalytic activity of H-beta-62 is probably due to the existence of these strong basic sites. As the only amorphous material, γAl2O3 was the most inactive one with just about 23% butene yield at 300°C for GVL decarboxylation reaction. According to the previous report, γ-Al2O3 was not truly a kind of efficient catalyst 20,21. Unlike zeolite, the Lewis acid sites of amorphous materials associated with extra framework aluminum. So, the Lewis sites in γ-Al2O3 cannot be comparable with that in beta zeolite with framework aluminum 31. In this case, it is the intrinsic activity of catalyst that determined GVL decarboxylation activity. Additionally, the influence of acid strength also was considered. The efficient catalysts (Nabeta-5 and H-Y-5.3) usually without strong acid sites according to Figure.1 and Figure.S5. On the contrary, the catalysts which had strong acid sites (H-beta-62, H-ZSM-5-200) exhibited relatively low performance on GVL decarboxylation. It could be deduced that acid type and density have a greater influence on GVL decarboxylation compare to acid strength. Furthermore, the influence of physical properties cannot be ignored. According to the previous literature, the kinetic diameter of GVL was 0.5-0.6nm 33. Whereas, the pore diameter of H-ZSM-5(0.55nm) was smiler to it. So, the diffusion limitation was a huge obstacle for GVL decarboxylation reaction by H-ZSM-5 catalyzing. The pore diameter of beta zeolites and H-Y5.3 zeolite were 0.62nm and 0.74nm, respectively. As a result, the diffusion limitation was 10


Page 11 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


decreasing. The BET surface area of H-Y-5.3 and beta samples were also large than H-ZSM-5 zeolites (Table1). Therefore, it is reasonable that beta samples were more active than HY and H-ZSM-5 zeolites. In addition, the liquid products and gas products were analyzed by GC-MS and GC. In the case of gas products, the main ingredients were CO2 and isomeric compound of butene. The proportion of different kinds of isomers were more or less. However, the 1-butene was the main ingredient among the isomeric butene with γ-Al2O3 catalyzing. For the liquid products, the case was different for different samples. For Na-beta-5, unreacted GVL was the main ingredient. Besides, it has a high selectivity to produce the isomers of octene and TMB (trimethylbenzene), and no pentenoic acid was detected. Importantly, this was not observed when other samples were used as catalysts. In the case of H-beta-25, unreacted GVL and pentenoic acid were the main ingredients. In addition, C9 and C10 alkene were the main by-products. For H-Y-5.3 and H-ZSM-5 samples, unreacted GVL and pentenoic acid were the main ingredient, besides, many kinds of oxygen compounds were formed in the liquid products probably due to polymerization of pentenoic acid in higher temperature (greater than or equal to 320°C). For H-beta-62 and γAl2O3, unreacted GVL was the main ingredient, and C10H18 was the main by-product. The components of these liquid products were not quantified, since it is outside the focus of this study. Overall, an obvious phenomenon was that the kinds and amounts of by-products increased and the amounts of GVL and pentenoic acid decreased with the increase of temperature. As the reaction product butene is sensitive to heat, it can polymerize easily with solid catalyzing 5,37,41. A lot of unknow compounds are inevitably synthesized with temperature increase. Whereas, this phenomenon was not obvious when Na-beta-5 was used as catalyst. For Na-beta-5, the main side products always were isomers of octene and TMB, which in accord with the previous report that beta is an excellent alkylation and oligomerization catalyst 30,38-41.

11



Page 12 of 25

3.4. Effects of acidic variation on catalytic conversion of GVL into butene Here, we have discovered that GVL decarboxylation over aluminosilicates appears relatively sensitive to Lewis acids in anhydrous environments according to the above discussion. For further study, three samples (H-ZSM-5-38, HY, Na-beta-5) were chosen to calcined at different temperatures for the purpose of changing the acid ratio of B/L. Then the calcined samples were used on GVL decarboxylation reaction respectively. The results are shown on Table.2. The ratio of B/L were measured by adsorbing of pyridine in situ infrared spectroscopy (Figure S7). Table 2. Decarboxylation of GVL to butene by using zeolites calcined at different temperature. Conversion

B acids

L acids

(μmol g −1)a

(μmol g −1)a

80

37

187

0.20

88

85

55

202

0.27

Na-beta-5(cal550) a

83

79

50

162

0.31

4

Na-beta-5(cal600) a

82

78

40

150

0.26

5

Na-beta-5(cal650) a

80

72

28

116

0.24

6

H-Y-5.3 (cal500) b

70

56

72

11

6.60

7

H-Y-5.3(cal550) b

74

63

48

33

1.45

8

H-Y-5.3(cal600) b

80

71

34

48

0.70

9

H-Y-5.3(cal650) b

85

76

19

71

0.27

10

H-ZSM-5-38(cal500) b

44

35

103

4.9

21.0

11


43

33

72

6.2

11.6

12


44

33

68

5.5

12.3

13


42

30

35

12

2.91

Entry

Catalyst

1

Na-beta-5(cal450) a

84

2

Na-beta-5(cal500) a

3

/%

Yield /%

B/L

Reaction conditions: GVL (1g), solid acid (0.1g), N2 (2MPa), 4.5h. Calcined conditions: 2h, at each temperature. a.280°C.

b. 300°C.

In the case of Na-beta-5, It has shown a slight variation of B/L ratio and a greater variation of total acid densities with the increase of calcined temperature for Na-beta-5 (Table 2). Therefore, the butene yield was proportional to the total acid densities since the variation of 12


Page 13 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


total acid densities have a greater influence on catalytic performance compare to B/L ratio (Figure S7, Table 2). For H-Y-5.3, the total acid densities were almost invariable with the change of calcined temperature (Figure S7, Table 2). Meanwhile, the B/L ratio decreased gradually by the increase of calcined temperature (Figure S7, Table 2). Therefore, the B/L ratio was the only variable with the change of calcined temperature. Results showed that the GVL conversion and butene yield increased with the decrease of B/L ratio (Table 2). Higher Lewis acid proportion leads to higher butene yield, which turned out directly that Lewis acid sites in zeolites were more active than Brønsted acid sites for GVL decarboxylation reaction. To the best of our knowledge, it was the first time to demonstrate that GVL decarboxylation reaction was sensitive to Lewis acid sites in aluminosilicates’ zeolites, which was opposite to the results of previous literatures

20,21.

For H-ZSM-5, the B/L ratio was decreased gradually by the

increase of calcined temperature (Figure S7, Table 2). But unlike H-Y-5.3, the total acid densities were decreased greatly with the increase of calcined temperature (Table 2). Therefore, the alter of catalytic activity of H-ZSM-5 was the results of both total acid densities variation and B/L ratio variation. Generally, the butene yield decreased slightly with the calcined temperature increase (Table 2). As mentioned above, both the total acid densities and B/L ratio can influence the catalytic performance of aluminosilicates’ zeolites on GVL decarboxylation. In the condition of keeping the total acid densities unchanged, Lewis acid sites appear more active than Brønsted acid sites, and they do contribute significantly to total butene yield in H-Y-5.3 zeolite. This result was credible since the effect of physical properties (BET, pore sizes etc.) and intrinsic activity among different samples were eliminated. Under this condition, the variation of B/L ratio was almost the only variable which can influence the catalytic activity of catalyst. What’s more, this result proved the conclusion above that Lewis acid sites was more active than Brønsted acid sites in aluminosilicates’ zeolites. So, it also can explain the catalytic behavior that high 13



Al content beta zeolite with abundant Lewis acid sites can efficiently catalyze GVL decarboxylation reaction.

80

80

60

60

40

40

20

20

0 0 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Catalyst content /%

100

100

80

80

60

60

40

40

20

20

0

0.0

0.5

a

2.5

0

80

60

60

40

40

20

20

0

0

280 300 320 Temperature / ℃

340

100

100

80

80

60

60

40

40

20

20

0

1

c

2

3 4 Time / h

5

6

GVL Conversion / %

80

Butene Yield / %

100

GVL Conversion / %

b

100

260

1.0 1.5 2.0 Pressure /Mpa

GVL Conversion / %

100 Butene Yield / %

100

GVL Conversion / %

Butene Yield / %

3.5. Effects of Reaction Parameters on Catalytic Conversion of GVL into butene.

Butene Yield / %

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 25

0

d

Figure .2. Effects of different reaction conditions on GVL decarboxylation reaction using Nabeta-5 catalysts: (a) catalyst content (b) pressure(c) temperature (d) reaction time. If not specified, the default reaction conditions were as follows: GVL(1g), catalyst (0.1g), temperature(300°C), N2 pressure (1.8Mpa), time (4.5h).

Based on the results above, Na-beta-5 was the most excellent catalyst and used for further investigation. The effects of catalyst content, reaction pressure, reaction temperature and reaction time were investigated, as showed in Figure.2. It shows the effect of catalyst loading for GVL decarboxylation reaction. As can be seen from it, the catalyst loading showed a significant effect on the GVL conversion and butene yield. With the addition of more and more catalyst, the GVL conversion and butene yield increased gradually. Butene yield was only 10% without beta catalyst but it sharply increased to 61% by loading 0.025g beta catalyst, and butene yield was further increased with further increase of the catalyst loading amount. However, the

14


Page 15 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


rate of increase was relatively small with the catalyst amount increased from 0.1g to 0.125g. The possible reason might be that the active acid sites of 0.1g catalyst were sufficient for GVL decarboxylation under given conditions. Furthermore, more octenes and TMBs were detected with the increase of catalyst loading amounts. The influence of N2 pressure on the GVL decarboxylation reaction was investigated and the results were shown in Figure.2b. It can be seen from the Chart that N2 pressure has a little effect on the GVL conversion and butene yield. Butene yield decreased slightly with the reaction pressure increase. Overall, the change of butene yield was not remarkable with the increase of N2 pressure. So, it is suitable to choose 0Mpa as initial reaction pressure. Whereas, with the increase of pressure, the yield of both octenes and TMBs were detected. The effect of reaction temperature on butene yield is presented in Figure.2c. As can be seen from it, the reaction temperature had a remarkable effect on the conversion of GVL into butene. Undoubtedly, higher reaction temperature lead to higher butene yield. At 240°C, only 31% butene yield could be obtained. But it sharply increased to 80% and 90% by the increase of temperature to 280°C and 300°C, respectively. The yield of butene increased slightly from 300°C to 340°C under tested conditions. So, it was sufficient to catalyze GVL decarboxylation at 300°C under given conditions. Therefore, 300°C was an appropriate reaction temperature for the GVL decarboxylation reaction under given conditions. The yield of both octenes and TMBs increased with reaction temperature increase. Catalytic conversion of GVL into butene with different reaction time was also carried out. As shown in Figure.2d, the GVL conversion and butene yield were increased gradually from 1h to 6h and reached the highest point in about 5 hours. With the extension of reaction time, an obvious phenomenon was that more light-yellow oily liquids could be obtained. And the main ingredient were also octenes and TMBs. So, it is suitable to react for 5h under given

15



conditions. 99.5% GVL conversion and 98% butene yield were obtained after condition optimizing. 3. 6. Kinetics and mechanism Studies on Catalytic Conversion of GVL into butene with Na-beta-5

2.5

Ea = 87.47KJ/mol lnA = 13.37

2.0

-3.5

1.5 1.0

-4.5 -5.0 -5.5

0.5

-6.0

0.0 -0.5

340℃ 320℃ 300℃ 280℃

-4.0

ln k (min-1)

ln(nGVL/mmol)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 25

b 1.64

1.68 1.72 1.76 103 T -1(K-1 )

1.80

a 0

100

200

300

400

500

600

700

Time / min Figure.3. (a) ln(n) versus reaction time for GVL conversion (b) Arrhenius plots of ln k based on different temperatures.

To study the GVL decarboxylation reaction kinetics, the experiments monitoring GVL conversion at different temperatures and times were carried out to obtain the kinetics parameters (Table S2). The linearity of Figure. 3a suggested that GVL decarboxylation with Na-beta-5 meet the first order kinetic model. So, the reaction rate constants (Table S2) were credible. Rate constants increased with reaction temperature increasing. The activation energy (Ea) and pre-exponential factor (A) were calculated by the Arrhenius equation with the experimental data: 𝑙𝑛𝑘 = 𝑙𝑛𝐴 ―

𝐸𝑎 𝑅𝑇

16


Page 17 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Arrhenius plots were drawn according to the reaction rate constants (TableS2), as showed in Figure 3(b). The values of A and Ea were obtained from the intercept and the slope, respectively. An activation energy of 87.47 kJ/mol was determined for GVL conversion, which was lower than the lowest value reported in the literature (92 kJ/mol) 19,21 According to the previous report, there were two reaction pathways for GVL decarboxylation reaction and the two-step mechanism was the main reaction pathway since the 18-20

intermediate pentenoic acid can be detected

and this pathway had a relatively lower

activation barrier (142 kJ/mol) 19,24. However, no pentenoic acid has been detected at each time and temperature point using Na-beta-5 as catalyst. Based on the above discuss, it is proposed the possible mechanism that GVL decarboxylation reaction was dominant by one-step pathway with Na-beta-5 catalyzing (Scheme 1). As can be seen from the Scheme 1, Lewis acid had a strong attraction for the lone pair electrons on oxygen atom of C-O bond, leading to the polarity of C-O band increasing. Therefore, it is easier for heterolysis of C-O covalent bond and as a consequence to decrease the trend of ring closure. Then the intermediates carbenium ions undergo a H-shift process and decarboxylates to form 1-butene and carbon dioxide.

L acid

L acid O

H3C

O

H3C

O

HC

H2C

H2C

CH2

L acid

H-shif t

O

H3C

HC

CH2

H2C O

CH2 +

CH

C-O leavage

L acid CH2

O

+

HC

H2C

O

H3C

O

CH

C-L leavage

C

H2C CH2

CH3

Scheme 1. Proposed mechanism of GVL decarboxylation catalyzed by Nabeta-5.

4. Conclusions

17


O

O


In summary, high Al beta zeolite (Si: Al=5) with a large number of Lewis acid sites was synthesized and used for GVL decarboxylation reaction first time. It was an excellent catalyst for GVL decarboxylation reaction in anhydrous environments due to its abundant Lewis acid sites and large pore diameter. Compare to other zeolites tested here, beta samples showed a remarkable catalytic activity, especially at low temperature. To our best knowledge, it is the first time to find Lewis acids were more active than Brønsted acids on GVL decarboxylation. Then, the physicochemical properties and their impact on catalytic activity were discussed in detail. Results shows that the intrinsic activity, acid amounts and pore size all have a significant effect on catalytic activity for GVL decarboxylation. Whereas, the strong basic sites in zeolites was a disadvantage to restrain GVL decarboxylation according to CO2-TPD. Furthermore, the effect of B/L ratio variation to GVL decarboxylation was studied. The butene yield increased with the increase of the proportion of Lewis acids when the total acid amount was almost unchanged. It is suggested that both Lewis acids and Brønsted acids in aluminosilicates’ zeolites could catalyze GVL decarboxylation. But Lewis acids in crystalline material was more active than Brønsted acids. The reaction kinetics was also researched and a relatively low activation energy (87.47KJ/mol) was obtained. At last, a possible reaction mechanism with Lewis acids was proposed.

18


Page 18 of 25

Page 19 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


ASSOCIATED CONTENT Supporting Information Characterization details of seven samples (H-ZSM-5-38, H-ZSM-5-200, H-Y-5.3, H-beta-25, H-beta-62, Na-beta-5, γ-Al2O3), including XRD patterns, Adsorption–desorption isotherms of N2, NH3-TPD profile, CO2-TPD profile, Pyridine-FT-IR spectrum. The SEM and EDS images of Na-beta-5 samples. Experimental details of kinetic parameters AUTHOR INFORMATION Corresponding Authors *Jiayu Xin. E-mail: [email protected] Tel./fax: +86-10-62558174. *Suojiang Zhang. E-mail: [email protected] ORCID Jiayu Xin: 0000-0002-0728-294X Suojiang Zhang: 0000-0002-9397-954X Notes The authors declare no competing financial interest. ACKNOWLEDGMENTS This work was financially supported by the National Key R&D Program of China (No.2018YFB1501600), the National Natural Science Foundation of China (No. 21878314, 21878292, 21576269, 21476234)

19



References (1) Kunkes, E. L.; Simonetti, D. A.; West, R. M.; Serrano-Ruiz, J. C.; Gärtner, C. A.; Dumesic J. A. Catalytic Conversion of Biomass to Monofunctional Hydrocarbons and Targeted LiquidFuel Classes. Sci. 2008, 322, 417-421. (2) Ragauskas, A. J.; Williams, C. K.; Davison, B. H.; Britovsek, G.; Cairney, J.; Eckert, C.A.; Frederick, W. J.; Hallett, J. P.; Leak, D. J.; Liotta, C. L.; Mielenz, J. R.; Murphy, R.; Templer, R.; Tschaplinski, T. The Path Forward for Biofuels and Biomaterials. Sci. 2006, 311, 484-489. (3) Huber, G. W.; Iborra, S.; Corma A. Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysts, and Engineering. Chem. Rev. 2006, 106, 4044-4098. (4) Simonetti, D. A.; Rass-Hansen, J.; Kunkes, E.L.; Soares, R. R.; Dumesic, J. A. Coupling of glycerol processing with Fischer–Tropsch synthesis for production of liquid fuels. Green Chem. 2007, 9, 1073-1083. (5) Salinas, A.L. M.; Sapaly, G.; Taarit, Y. B.; Vedrine, J.C.; Essayem, N. Continuous supercritical iC4/C4= alkylation over H-Beta and H-USY: Influence of the zeolite structure. Appl. Catal., A. 2008, 336, 61–71. (6) Alonso, D. M.; Wettstein, S. G.; Dumesic, J. A. Bimetallic catalysts for upgrading of biomass to fuels and chemicals. Chem. Soc. Rev. 2012, 41,8075-8098. (7) Chatterjee, C.; Pong, F.; Sen A. Chemical conversion pathways for carbohydrates. Green Chem. 2015, 17, 40-71. (8) Serrano-Ruiz, J.C.; Braden, D.J.; West, R.M.; Dumesic, J. A. Conversion of cellulose to hydrocarbon fuels by progressive removal of oxygen. Appl. Catal., B. 2010, 100, 184-189. (9) Chheda, J. N.; Huber, G. W.; Dumesic, J. A. Liquid‐Phase Catalytic Processing of Biomass‐Derived Oxygenated Hydrocarbons to Fuels and Chemicals. Angew. Chem. Int. Ed. 2007, 46, 7164-7183.

20


Page 20 of 25

Page 21 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(10) Sen, S. M.; Henao C. A., Braden, D. J.; Dumesic, J. A.; Maravelias, C.T. Catalytic conversion of lignocellulosic biomass to fuels: Process development and technoeconomic evaluation. Chem. Eng. Sci. 2012, 67, 57–67. (11) Huber, G. W.; Chheda, J. N.; Barrett, C. J.; Dumesic, J. A. Production of Liquid Alkanes by Aqueous-Phase Processing of Biomass-Derived Carbohydrates. Sci. 2005, 308 ,1446-1449. (12) Xin, J.Y.; Zhang, S.J.; Yan, D.X.; Ayodele, O.; Lu, X.M.; Wang, J.J. Formation of C–C bonds for the production of bio-alkanes under mild conditions. Green Chem., 2014, 16, 35893595. (13) Tuck, C. O.; Pérez, E.; Horváth, I.T.; Sheldon, R.A.; Poliakoff, M. Valorization of Biomass: Deriving More Value from Waste. Sci. 2012, 337, 695-699. (14) Yan, K.; Lafleur, T.; Wu, X.; Chai, J.J.; Wu, G.S.; Xie, X.M. Cascade upgrading of γvalerolactone to biofuels. Chem. Commun. 2015, 51, 6984-6987. (15) Du, X.L.; Liu, Y.M.; Wang, J.Q.; Cao, Y.; Fan, K. Catalytic conversion of biomassderived levulinic acid into γ-valerolactone using iridium nanoparticles supported on carbon nanotubes. Chin. J. Catal. 2013,34, 993-1001. (16) Luo, W.H.; Deka, U.; Beale, A. M.; van Eck, E.R.H.; Bruijnincx, P. C.A.; Weckhuysen, B. M. Ruthenium-catalyzed hydrogenation of levulinic acid: Influence of the support and solvent on catalyst selectivity and stability. J. Catal. 2013, 301,175-186. (17) Lange, J.P.; van de Graaf, W. D; Haan, R.J. Conversion of Furfuryl Alcohol into Ethyl Levulinate using Solid Acid Catalysts. ChemSusChem. 2009, 2, 437-441. (18) Bond, J. Q.; Alonso, D. M.; Wang, D.; West, R. M.; Dumesic, J. A. Integrated Catalytic Conversion of γ-Valerolactone to Liquid Alkenes for Transportation Fuels. Sci. 2010,327,1110-1114.

21



(19) Bond, J. Q.; Wang, D.; Alonso, D. M.; Dumesic, J. A. Interconversion between γvalerolactone and pentenoic acid combined with decarboxylation to form butene over silica/alumina. J. Catal. 2011, 281, 290-299. (20) Wang, D.; Hakim, S. H.; Alonso, D. M.; Dumesic, J. A. A highly selective route to linear alpha olefins from biomass-derived lactones and unsaturated acids. Chem. Commun.2013, 49, 7040-7042. (21) Kellicutt, A. B.; Salary, R.; Abdelrahman, O.A. and Bond, J. Q. An examination of the intrinsic activity and stability of various solid acids during the catalytic decarboxylation of γvalerolactone. Catal. Sci. Technol.2014, 4, 2267-2279. (22) Bond, J. Q.; Jungong, C. S.; Chatzidimitriou, A. An examination of the intrinsic activity and stability of various solid acids during the catalytic decarboxylation of γ-valerolactone. J. Catal. 2016, 344, 640–656. (23) Bond, J. Q.; Alonso, D. M.; West, R. M.; Dumesic, J. A. γ-Valerolactone Ring-Opening and Decarboxylation over SiO2/Al2O3 in the Presence of Water. Langmuir. 2010, 26(21), 16291-16298. (24) Khan, T. S.; Gupta, S.; Bandodkar, P.; Alam, M. I.; Ali Haider, M. On the role of oxocarbenium ions formed in Brønsted acidic condition on γ-Al2O3 surface in the ring-opening of γ-valerolactone. Appl. Catal., A.2018, 560, 66-72. (25) Corma, A.; González-Alfaro, V.; Orchillés, A.V. The role of pore topology on the behaviour of FCC zeolite additives. Appl. Catal., A. 1999, 187, 245-254. (26) Otomo, R.; Müller, U.; Feyen, M.; Yilmaz, B.; Meng, X.J.; Xiao, F.S.; Gies, H.; Bao, X.H.; Zhang, W.P.; Vos.D.D.; Yokoi, T. Development of a post-synthetic method for tuning the Al content of OSDA-free Beta as a catalyst for conversion of methanol to olefins.Catal. Sci. Technol. 2016, 6, 713-721.

22


Page 22 of 25

Page 23 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(27) Otomo, R.; Yokoi, T.; and Tatsumi, T. OSDA‐Free Zeolite Beta with High Aluminum Content Efficiently Catalyzes a Tandem Reaction for Conversion of Glucose to 5Hydroxymethylfurfural. ChemCatChem.2015,7, 4180-4187. (28) Winoto, H. P.; Fikri, Z.A.; Ha, J.M.; Park, Y.K.; Lee, H.; Suh, D.J.; Jae, J. Heteropolyacid supported on Zr-Beta zeolite as an active catalyst for one-pot transformation of furfural to γvalerolactone. Appl. Catal., B. 2019, 241, 588-597. (29) Yan, N.; Ren, B.Z.; Wu, B.; Bao, D.; Zhang, X.P.; Wang, J.H. Multi-objective optimization of biomass to biomethane system. Green Energy & Environment. 2016,1, 156165. (30) Villegas, J.I.; Kumar, N.; Heikkila¨, T.; Lehto, V.-P.; Salmi, T.; Murzin, D.Y. A study on the dimerization of 1-butene over Beta zeolite. Top. Catal. 2007, 45, 187-189. (31) Ward, J. W. Hydrocracking processes and catalysts. Fuel Process. Technol. 1993, 35, 5585. (32) Fang, W.T.; Hu, H.L.; Dong, P.; Ma, Z.S.; He, Y.L.; Wang, L.; Zhang, Y.J. Improvement of furanic diether selectivity by adjusting Brønsted and Lewis acidity. Appl. Catal., A. 2018, 565, 146–151. (33) Jae, J.; Tompsett, G.A.; Foster, A.J.; Hammond, K.D.; Auerbach, S. M.; Lobo, R. F.; Huber, G. W. Investigation into the shape selectivity of zeolite catalysts for biomass conversion. J. Catal. 2011, 279, 257-268. (34) Deshpande, N.; Parulkar, A.; Joshi, R.; Diep, B.; Kulkarni, A.; Brunelli, N.A. Epoxide ring opening with alcohols using heterogeneous Lewis acid catalysts: Regioselectivity and mechanism. J. Catal. 2019,.370, 46–54. (35) Alvira, P.; Tomas-Pejo, E.; Ballesteros, M.; Negro, M. J. Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review. Bioresour. Technol. 2010, 101, 4851-4861. 23



(36) Gallezot, P. Conversion of biomass to selected chemical products. Chem. Soc. Rev., 2012, 41,1538-1558. (37) Loenders, R.; Jacobs, P. A.; Martens, J. A. Alkylation of Isobutane with 1-Butene on Zeolite Beta. J. Catal. 1998, 176 ,545-551. (38) Yoo, K.; Smirniotis, P. G. The influence of Si/Al ratios of synthesized beta zeolites for the alkylation of isobutane with 2-butene. Appl. Catal., A. 2002, 227, 171–179. (39) EKINE, Y. S.; CHIKAWA, Y. I.; AJIMA, Y. T.; AKABAYASHI, K. N.; ATSUKATA, M. M.; IKUCHI, E. K.; Petrol, J. J. Alkylation of Isobutane by 1-Butene over H-beta Zeolite in CSTR (Part 1) Effects of Zeolite-structures and Synthesis Methods on Alkylation Performance. J. Jpn. Pet. Inst. 2012 55, (5), 299-307. (40) Costa, B.O. D.; Querini, C.A. Isobutane alkylation with solid catalysts based on beta zeolite. Appl. Catal., A. 2010,.385,144-152. (41) Jin, K.T.; Zhang, T.; Yuan, S.J.; Tang, S.W. Regulation of isobutane/1-butene adsorption behaviors on the acidic ionic liquids-functionalized MCM-22 zeolite. Chin. J. Chem. Eng. 2018, 26, 127-136.

24


Page 24 of 25

Page 25 of 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table of Contents

O

O

573K, no water Lewis acid beta zeolite as efficient catalyst

98%Butene

99.8% γ-Valerolactone

25


High aluminum content Beta zeolite as an active Lewis acid catalyst

Recommend Documents