Electroanalytical comparison of catalyst-support interfaces in In2O3/CeO2 and In2O3/ZrO2 for CO2 reduction to formate

In 2 O 3 supported on ZrO 2 and CeO 2 was developed for CO 2 -to-formate electroreduction. • Distinct support effects of ZrO 2 and CeO 2 on In 2 O 3 active site were identified. • CeO 2 tunes electronic structure of In species and boosts the catalytic performance. • In 2 O 3 /CeO 2 delivers higher current density and Faradaic efficiency than In 2 O 3 /ZrO 2 . • The In 2 O 3 /CeO 2 catalyst maintains stable operation for 50 h at 100 mA cm −2 . Developing efficient electrocatalysts for the selective CO 2 electroreduction to formate is important for achieving carbon neutrality. Herein, In 2 O 3 /ZrO 2 and In 2 O 3 /CeO 2 catalysts were fabricated by combining MOF-derived oxide supports with incipient wetness impregnation and subsequent thermal treatment. Comparative studies reveal that CeO 2 affords a more favorable catalyst-support interface than the ZrO 2 support, resulting in enhanced activity and selectivity for formate production. In a flow cell, the optimized In 2 O 3 /CeO 2 catalyst achieves a formate Faradaic efficiency of 90.0% at −1.37 V vs. RHE with a current density of 177 mA cm −2 , significantly outperforming the In 2 O 3 /ZrO 2 catalyst. Combined structural characterization and kinetic analysis indicate that the CeO 2 support improves the electronic structure of In species, thereby facilitating the adsorption and conversion of key intermediates and thereby improving the intrinsic reactivity for formate formation. Moreover, the In 2 O 3 /CeO 2 catalyst maintains stable operation for 50 h at 100 mA cm −2 . This work highlights the critical role of support effects in regulating In-based active sites and provides insights into the rational design of efficient catalysts for the selective CO 2 -to-formate electroreduction. A series of In 2 O 3 /ZrO 2 and In 2 O 3 /CeO 2 catalysts were prepared for ECR to formate. The CeO 2 affords a more favorable catalyst-support interface than the ZrO 2 support, resulting in enhanced activity and selectivity for formate production. Download: Download high-res image (117KB) Download: Download full-size image