Wang Dongliang, Li Yanwei, Zhao Yu, Ji Dong, Dong Peng, Li Guixian
College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou, 730050, People's Republic of China.
BMC Chem. 2021 May 21;15(1):35. doi: 10.1186/s13065-021-00761-2.
The alkylation of benzene with methanol is an important synthetic method that is widely used in various chemical production processes. However, obtaining a high selectivity for xylene and annihilating the MTO side reaction remain challenges.
In this work, a Ru/HZSM-5 catalyst was prepared using ZSM-5 as the precursor by a chemical precipitation method. Both XRD and TEM confirmed that Ru nanoparticles were evenly dispersed on the surface of the ZSM-5. The catalytic performance of benzene alkylation with methanol on the Ru/HZSM-5 catalyst was investigated. The results showed that the Ru/HZSM-5 catalyst could completely annihilate the MTO side reaction with a high conversion efficiency of benzene and selectivity for xylene, which resulted from the large gap between the transgression energy value of Ru and the ionization potential value of benzene, and the acidity of the catalyst changed greatly.
These findings may offer not only a new and efficient multifunctional catalyst for benzene alkylation but also fundamental insight into the catalytic mechanism of the Ru/HZSM-5 catalyst.
苯与甲醇的烷基化反应是一种重要的合成方法,广泛应用于各种化工生产过程中。然而,实现对二甲苯的高选择性以及消除甲醇制烯烃(MTO)副反应仍然是具有挑战性的问题。
在本工作中,以ZSM-5为前驱体,通过化学沉淀法制备了Ru/HZSM-5催化剂。X射线衍射(XRD)和透射电子显微镜(TEM)均证实Ru纳米颗粒均匀分散在ZSM-5表面。考察了Ru/HZSM-5催化剂上苯与甲醇烷基化反应的催化性能。结果表明,Ru/HZSM-5催化剂能够完全消除MTO副反应,同时苯具有较高的转化效率和对二甲苯的选择性,这是由于Ru的逸出功值与苯的电离势值之间存在较大差距,且催化剂的酸度发生了很大变化。
这些发现不仅可为苯烷基化反应提供一种新型高效的多功能催化剂,还可为Ru/HZSM-5催化剂的催化机理提供基本认识。