晶种和有机模板剂接力导向合成ZSM-5分子筛及其催化性能

摘要/Abstract

摘要： 以晶种和有机模板剂接力导向（简称接力法）合成出ZSM-5分子筛，其晶型、形貌、体相硅铝比和孔结构性质等均与传统法合成的ZSM-5分子筛接近。对比接力法和传统法制备的ZSM-5分子筛在以1,3,5-三异丙苯催化裂化为探针反应上的催化性能，结果是接力法制备的ZSM-5分子筛上的1,3,5-三异丙苯转化率较低，表明此方法制备的ZSM-5分子筛表面富硅贫铝。进一步，将两种方法合成的分子筛制备成异构化催化剂，应用于催化乙苯脱乙基型二甲苯异构化反应，结果表明，相同反应条件下接力法制备的ZSM-5分子筛上的乙苯转化率更高，而异构化活性和二甲苯损失率更低。可见，晶种和有机模板剂接力导向是制备铝含量不同的核壳分子筛的一种可行方法。

关键词: 分子筛, 乙苯, 脱乙基, 二甲苯异构化, 晶种, 有机模板剂

Abstract: ZSM-5 zeolite was synthesized by the relay-oriented method of crystal seed and organic template agent, and the obtained ZSM-5 zeolite has similar crystalline structure, morphology, bulk Si/Al ratio, and pore structure to those of ZSM-5 zeolite synthesized by traditional methods. The performance of ZSM-5 zeolite synthesized by the relay method and traditional methods was compared on the reaction with 1,3,5-triisopropylbenzene catalytic cracking as probe. The results showed that the conversion of 1,3,5-triisopropylbenzene of ZSM-5 zeolite prepared by the relay method was low, which indicated that the surface of ZSM-5 zeolite prepared by the this method was rich in silicon and poor in aluminum. Furthermore, the zeolites synthesized by both methods were used as isomerization catalysts for ethylbenzene isomerization. Under the same reaction conditions, the ethylbenzene conversion of ZSM-5 zeolite prepared by the relay method was higher, but the isomerization activity and xylene loss rate were lower. It can be seen that crystal seed and organic template agent relaying is a feasible method to prepare core-shell molecular sieve with different aluminum content.

Key words: molecular sieve, ethylbenzene, deethylation, xylene isomerization, seed, organic template agent

张燕挺任嘉欣郭云鸦李晓峰窦涛. 晶种和有机模板剂接力导向合成ZSM-5分子筛及其催化性能[J]. 石油炼制与化工, 2024, 55(7): 62-68.

参考文献

[1]Miao L, Hong Z, Zhao G, et al.Mo-Modified ZSM-5 zeolite with intergrowth crystals for high-efficiency catalytic xylene isomerization[J].Catalysis Science & Technology, 2021, 11(14):4831-4837 [2]Miao L, Hong Z, Wang X, et al.Catalytic synergistic effect of bis-ZSM-5 zeolite with different crystal sizes for xylene isomerization[J].Microporous and Mesoporous Materials, 2022, 332:111718-111726 [3] Amelse J A.On the mechanism for ethyl transfer and removal from ethylbenzene during commercial xylene isomerization[J]. Microporous and Mesoporous Materials, 2019, 278: 275-279. [4]Zhai Y, Zhang S, Shang Y, et al.Boosting the turnover number of core-shell Al-ZSM-5@ B-ZSM-5 zeolite for methanol to propylene reaction by modulating its gradient acid site distribution and low consumption diffusion[J].Catalysis Science & Technology, 2019, 9(3):659-671 [5]Zheng R, Liu Z, Wang Y, et al.Industrial catalysis: strategies to enhance selectivity[J].Chinese Journal of Catalysis, 2020, 41(7):1032-1038 [6]Carpenter J R, Yeh S, Zones S I, et al.Further investigations on Constraint Index testing of zeolites that contain cages[J].Journal of Catalysis, 2010, 269(1):64-70 [7]Lv J, Hua Z, Zhou J, et al.Surface-passivated hierarchically structured ZSM5 zeolites: high-performance shape-selective catalysts for para-xylene production[J].ChemCatChem, 2018, 10(10):2278-2284 [8]Zhang Y T, Zhang N N, Chen S L, et al.Surface dealuminated Beta zeolites supported WO3 catalyst and its catalytic performance in tetralin hydrocracking[J].Petroleum Science, 2022, 19(6):3116-3123 [9]Liang T, Chen J, Qin Z, et al.Conversion of methanol to olefins over H-ZSM-5 zeolite: Reaction pathway is related to the framework aluminum siting[J].Acs Catalysis, 2016, 6(11):7311-7325 [10]Knott B C, Nimlos C T, Robichaud D J, et al.Consideration of the aluminum distribution in zeolites in theoretical and experimental catalysis research[J].ACS Catalysis, 2018, 8(2):770-784 [11]Chawla A, Li R, Jain R, et al.Cooperative effects of inorganic and organic structure-directing agents in ZSM-5 crystallization[J].Molecular Systems Design & Engineering, 2018, 3(1):159-170 [12] Miyake K, Hirota Y, Ono K, et al.Direct and selective conversion of methanol to para-xylene over Zn ion doped ZSM-5/silicalite-1 core-shell zeolite catalyst[J]. Journal of Catalysis, 2016, 342: 63-66. [13]Inagaki S, Sato K, Hayashi S, et al.Mechanochemical approach for selective deactivation of external surface acidity of ZSM-5 zeolite catalyst[J].ACS Applied Materials & Interfaces, 2015, 7(8):4488-4493 [14] Losch P, Boltz M, Bernardon C, et al.Impact of external surface passivation of nano-ZSM-5 zeolites in the methanol-to-olefins reaction[J]. Applied Catalysis A: General, 2016, 509: 30-37. [15]Wang Y, Wu Q, Meng X, et al.Insights into the organotemplate-free synthesis of zeolite catalysts[J].Engineering, 2017, 3(4):567-574 [16]Shen H, Liu M, Li J, et al.Promising strategy to synthesize ZSM-5@ Silicalite-1 with superior catalytic performance for catalytic cracking reactions[J].Industrial & Engineering Chemistry Research, 2021, 60(25):9098-9106 [17] 张燕挺, 党辉, 张妮妮, 等.表面活性剂-模板化法制备多级孔β沸石及其四氢萘加氢裂化制苯, 甲苯, 二甲苯的催化性能[J].无机化学学报, 2022(007):038. [18]Zhai Y, Zhang S, Shang Y, et al.Boosting the turnover number of core-shell Al-ZSM-5@ B-ZSM-5 zeolite for methanol to propylene reaction by modulating its gradient acid site distribution and low consumption diffusion[J].Catalysis Science & Technology, 2019, 9(3):659-671