Hydrogenation of CO_(2) to p-xylene over ZnZrO_(x)/hollow tubular HZSM-5 tandem catalyst  

作　　者：Haifeng Tian Zhiyu Chen Haowei Huang Fei Zha Yue Chang Hongshan Chen 

机构地区：[1]College of Chemistry&Chemical Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China [2]Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education,Lanzhou 730070,Gansu,China [3]College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China

出　　处：《Journal of Energy Chemistry》2024年第12期725-737,共13页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(22268039);the Natural Science Foundation for Distinguished Young Scholars of Gansu Province(23JRRA682)。

摘　　要：The conversion of CO_(2) into specific aromatics by modulating the morphology of zeolites is a promising strategy.HZSM-5 zeolite with hollow tubular morphology is reported.The morphology of zeolite was precisely controlled,and the acid sites on its outer surface were passivated by steam-assisted crystallization method,so that the zeolite exhibits higher aromatic selectivity than sheet HZSM-5 zeolite and greater p-xylene selectivity than chain HZSM-5 zeolite.The tandem catalyst was formed by combining hollow tubular HZSM-5 zeolites with ZnZrO_(x)metal oxides.The para-selectivity of p-xylene reached 76.2%at reaction temperature of 320℃,pressure of 3.0 MPa,and a flow rate of 2400 mL g^(-1)h^(-1)with an H_(2)/CO_(2) molar ratio of 3/1.Further research indicates that the high selectivity of p-xylene is due to the pore structure of hollow tubular HZSM-5 zeolite,which is conducive to the formation of p-xylene.Moreover,the passivation of the acid site located on the outer surface of zeolite effectively prevents the isomerization of p-xylene.The reaction mechanism of CO_(2) hydrogenation over the tandem catalyst was investigated using in-situ diffuse reflectance Fourier transform infrared spectroscopy and density functional theory.The results showed that the CO_(2) to p-xylene followed a methanol-mediated route over ZnZrO_(x)/hollow tubular HZSM-5 tandem catalysts.In addition,the catalyst showed no significant deactivation in the 100 h stability test.This present study provides an effective strategy for the design of catalysts aimed at selectively preparing aromatics through CO_(2)hydrogenation.

关 键 词：Hollow tubular HZSM-5 zeolite Tandem catalyst CO_(2)hydrogenation P-XYLENE Reaction mechanism 

分 类 号：TQ426[化学工程] TQ241.13