Hydrogenation of CO2 to light olefins over Ga2O3-ZIF-8 tandem catalyst

作者：Haifeng Tian, Haowei Huang, Zhiyu Chen, Fei Zha, Xiaojun Guo, Xiaohua Tang, Yue Chang, Hongshan Chen · 发表于：Separation and Purification Technology · 年份：2024 · DOI：10.1016/j.seppur.2024.130281 · 被引用次数：16 · 研究领域：Carbon dioxide utilization in catalysis、Metal-Organic Frameworks: Synthesis and Applications、Catalysts for Methane Reforming

Tandem catalysts composed of metal oxides and zeolites have demonstrated significant potential for the hydrogenation of CO 2 to light olefins. However, their development is hindered by the competing reverse water–gas shift reaction and carbon accumulation on the zeolite surface. To address these challenges, we developed a series of innovative tandem catalysts by substituting conventional zeolites with ZIF-8. Our research primarily focused on examining the effects of metal species and content, as well as the particle size of ZIF-8, on catalytic performance. Notably, we achieved a CO 2 conversion of 20.2 % and a light olefins selectivity of 73.6 % using a catalyst with 20 % Ga 2 O 3 content and a ZIF-8 particle size of 100 nm at a reaction temperature of 340 °C and pressure of 3.0 MPa. In order to improve the stability of the catalyst, ZIF-8 was modified with La to improve its thermal stability. A CO 2 conversion of 23.5 % and a light olefins selectivity of 66.5 % were maintained after 50 h of continuous reaction. While the catalytic activity of La-modified catalysts is slightly lower than that of unmodified ones, their superior stability makes them more suitable for thermal catalytic hydrogenation of CO 2 . Various characterizations and theoretical calculations revealed that La modification not only enhanced the thermal stability of catalyst but also improved its adsorption and activation capabilities for the reacting gases. Furthermore, the reaction mechanism of CO 2 hydrogen...