Redox-Mediated Interfacial Restructuring of Supported In<sub>2</sub>O<sub>3</sub> to Drive CO<sub>2</sub> Hydrogenation to Methanol
Feifan Gao, Yuxin Wang, Yudong Zhao, Kaizhi Wang, Wendi Guo, Zehui Sun, Yifeng Zhu, Heyong He, Yongmei Liu, Yong Cao
Abstract
The successful hydrogenative conversion of CO 2 to methanol necessitates effective strategies to finely tune the interfacial structures for optimal performance. Herein, we present a redox-mediated interfacial restructuring approach adopted to enhance the catalytic activity of supported In 2 O 3 for efficient CO 2 -to-methanol conversion. A sequential H 2 /O 2 reduction–reoxidation treatment was applied to markedly alter the interfacial architecture and electronic properties of In 2 O 3, resulting in an oxygen vacancy site (OV)-abundant In 2 O 3– x patch-like overlayer on monoclinic ZrO 2 . This architectural optimization maximizes the availability of active sites and promotes heterolytic H 2 dissociation along with associative CO 2 activation at the interfacial In–O–Zr sites, enabling highly effective catalysts that remain active while being stable against structural reconstruction during CO 2 hydrogenation to methanol. Additionally, this redox treatment proved to be effective in restoring activity in deactivated 15In/Zr catalysts made solely via simple impregnation, while also enhancing their inherent stability. This work emphasizes the effectiveness of this method in enhancing In 2 O 3 catalyst performance, while underscoring the critical role of key evaluation metrics (KEMs), including the dispersion degree, anti-overreduction factor, OV density, relative abundance of interfacial In–O–Zr sites, and In average valence state, in advancing the development of In-based catalysts for methanol synthesis. These results set new prospects for developing efficient and stable heterogeneous catalysts to facilitate essential chemical synthesis under CO 2 utilization conditions.