Tandem catalysts of different crystalline In2O3/sheet HZSM-5 zeolite for CO2 hydrogenation to aromatics

Haifeng Tian; Chunxue Jiao; Fei Zha; Xiaojun Guo; Xiaohua Tang; Yue Chang; Hongshan Chen

doi:10.1016/j.jcis.2023.09.168

Tandem catalysts of different crystalline In₂O₃/sheet HZSM-5 zeolite for CO₂ hydrogenation to aromatics

J Colloid Interface Sci. 2024 Jan;653(Pt B):1225-1235. doi: 10.1016/j.jcis.2023.09.168. Epub 2023 Sep 30.

Authors

Haifeng Tian¹, Chunxue Jiao², Fei Zha³, Xiaojun Guo², Xiaohua Tang², Yue Chang⁴, Hongshan Chen⁵

Affiliations

¹ College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China. Electronic address: thfnwnu@163.com.
² College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China.
³ College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China. Electronic address: zhafei@nwnu.edu.cn.
⁴ College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China; Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Lanzhou 730070, Gansu, China.
⁵ College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China.

PMID: 37797498
DOI: 10.1016/j.jcis.2023.09.168

Abstract

In tandem catalysts, not only good synergy between the two active components is required, but also the precise control of the spatial distribution between the two active components of metal oxides and zeolite is crucial for the migration and conversion of reaction intermediates in the direct conversion of CO₂ to hydrocarbons. The correlation between the metal and the acidic site of zeolite has traditionally been simplified as "the closer, the better". However, it should be noted that this principle only holds true for a portion of tandem catalysts. Therefore, this paper studied the effect of different crystalline In₂O₃ (cubic phase, hexagonal phase, and mixed cubic/hexagonal phase) and sheet HZSM-5 zeolite tandem catalysts on the activity of CO₂ hydrogenation reaction under different spatial distribution. The generalized gradient approximation (GGA) of density functional theory (DFT) were used to simulate the adsorption energy of CO₂ by oxygen vacancy on c-In₂O₃(111) and h-In₂O₃(104) planes, it was found that O_v1 on c-In₂O₃(111) and O_v4 on h-In₂O₃(104) had the strongest adsorption energy for CO₂. In addition, it has been observed that the proximity of the two active components (e.g., during mortar mixing) results in decreased catalytic performance. This is due to the migration of metal In, which neutralizes the acid sites of zeolites and leads to inefficient conversion of methanol reaction intermediates to aromatics. As a result, CO₂ conversion and aromatic selectivity are decreased.

Keywords: CO(2) hydrogenation; Different crystalline In(2)O(3); Sheet HZSM-5 zeolite; Spatial distribution.