Synergistic effects of ZnO–ZrO2@SAPO-34 core-shell catalyst in catalyzing CO2 hydrogenation for the synthesis of light olefins
Peng Lu, Xiaoning Chang, Wenjia Yu, Qianwen Hu, Kime Mala Ali, Chuang Xing, Ce Du, Zhixiang Yang, Shuyao Chen
Abstract
As a method for valorizing CO 2 emissions, hydrogenation of CO 2 into olefins remains viable. Herein, ZnO–ZrO 2 and SAPO-34 were prepared and used as bifunctional catalysts in light olefins synthesis through CO 2 hydrogenation. The combination of the two components includes layered filling, physically mixing, physically grinding , and core-shell composite. Based on the evaluation, different combinations resulted in diverse product distributions. ZnO–ZrO 2 @SAPO-34 core-shell catalysts are better suited for promoting synergistic effects, which facilitate light olefin production. Due to the unique core-shell structure, appropriate weak acidity, and moderate basicity , the light olefins selectivity was enhanced. Further, the calcination time and core-shell mass ratio were optimized over the ZnO–ZrO 2 @SAPO-34 core-shell catalyst to investigate the synergistic effects between catalytic structure and catalytic performance. With a 3:1 core-shell mass ratio and 3 h of calcination at 550 °C, the optimal ZnO–ZrO 2 @SAPO-34 (3:1) catalyst was obtained, which exhibited 73% selectivity to light olefins with CO 2 conversion of 16.1%, whereas the selectivity of CO and CH 4 was lower than 44% and 1.5%, respectively. This study provides new insights into the design and optimization of ZnO–ZrO 2 @SAPO-34 core-shell catalysts for CO 2 hydrogenation and synthesis of light olefins.