HF改性的Pt/ZSM-5催化剂在苯和甲醇烷基化反应中的应用

doi:10.11944/j.issn.1000-0518.2016.05.150418

摘要/Abstract

摘要：

以HF改性的Pt/ZSM-5为催化剂,研究了其在苯和甲醇烷基化反应的应用,并用XRD、NH₃-TPD、BET等表征方法研究了改性前后催化剂酸性和孔结构变化。结果表明,经HF改性后,Pt/ZSM-5催化剂的酸性增强、酸量增加,苯和甲醇烷基化反应性能明显提升。 3%HF-0.2%Pt/ZSM-5催化剂催化苯和甲醇烷基化反应时,甲苯和二甲苯选择性达到92.20%。但是,HF负载量大于6%时,HF脱除的部分骨架硅和骨架铝会堆积在催化剂孔道内部,限制了反应物和产物的扩散,造成其催化性能下降。通过计算得到了HF改性的Pt/ZSM-5催化剂上苯和甲醇烷基化反应的活化能为118 kJ/mol。

关键词: ZSM-5, HF, 苯, 甲醇, 烷基化

Abstract:

Hydrofloride modified Pt/ZSM-5 catalysts were studied and applied in benzene alkylation with methanol. The effects of acidity and pore structures of the catalysts were studied by NH₃-TPD and N₂ adsorption. The results show that the acidity and the amount of acidic sites of Pt/ZSM-5 are increased by HF modification and the catalytic performance in benzene methylation with methanol is also enhanced. The selectivity of toluene and xylene can reach to 92.20% when 3%HF-0.2%Pt/ZSM-5 catalyst is used in benzene methylation with methanol. When the loading of HF is more than 6%, partially removed aluminum and silicon from the zeolite framework will block the pores of zeolite resulting in decreasing diffusions of reactants and products, and eventually reducing catalytic performance of zeolites. The calculated activation energy of benzene methylation with methanol in HF modified Pt/ZSM-5 catalyst is 118 kJ/mol.

Key words: ZSM-5, HF, benzene, methanol, methylation

刘司,闻振浩,杨大强,朱学栋. HF改性的Pt/ZSM-5催化剂在苯和甲醇烷基化反应中的应用[J]. 应用化学, 2016, 33(5): 571-576.

LIU Si,WEN Zhenhao,YANG Daqiang,ZHU Xuedong. Application of HF Modified Pt/ZSM-5 Catalyst in Benzene Methylation with Methanol[J]. Chinese Journal of Applied Chemistry, 2016, 33(5): 571-576.

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