Mesoporous p-block metal oxide (In2O3, SnO2, Bi2O3)-ZrO2 catalysts toward electrocatalytic CO2 reduction to formate

Electrocatalytic CO 2 reduction (ECR) to high-value formic acid is an important approach for realizing carbon resource recycling and renewable energy storage. A key challenge in this process is the development of highly efficient and stable catalysts. In this work, three types of mesoporous catalysts, In 2 O 3 -ZrO 2 , SnO 2 -ZrO 2 , and Bi 2 O 3 -ZrO 2 , were prepared through a one-step method. The influence of type and existing state of active components on catalytic performance was researched in depth. These results indicate that the introduced active components exhibit a strong interaction with ZrO 2 support and exist as a highly dispersed state in the support. Among the prepared catalysts, the In 2 O 3 -ZrO 2 demonstrates superior activity and stability, achieving a formate Faraday efficiency of 90 % and a current density of 110 mA cm −2 at −1.17 V vs. RHE, while maintaining stable performance over an 80 h long-term ECR test. In addition, the mesoporous material with high specific surface area provides a greater number of active sites, thus contributing to the enhanced catalytic performance. This study provides a new catalyst synthesis strategy for ECR to formate and offers guidance for preparing high-efficiency catalysts.