Synergistic effect of hybrid support with carbon nitride and carbon black on Ag catalyst for efficient CO2 reduction to CO

Abstract

In electrochemical CO₂ reduction reactions (CO₂RR), carbon-based materials are widely used as catalyst supports to ensure high performance. However, surface modifications of carbon-based materials are frequently necessary for the uniform dispersion of the active materials, which makes the fabrication procedure for catalysts more complicated and which can result in issues such as reduced hydrophobicity. To address these challenges, a hybrid support catalyst loaded with Ag on a support composed of carbon nitride and carbon black is proposed to mitigate the need for a surface modification while simultaneously enhancing the electrochemical activity in CO₂RR. The hybrid support provides CO₂ affinity, improved active metal dispersion, high conductivity, and increased hydrophobicity, collectively leading to enhanced catalytic performance. The AgCN7CB3 catalyst achieves Faradaic efficiency and a partial current density for CO of 96 % and −287 mA/cm², respectively, at −1.6 V, and maintains stability for 160 h at −100 mA/cm². Compared to single support catalysts, the AgCNCB catalyst exhibits superior performance with regard to CO productivity and stability. These results demonstrate that hybrid supports catalysts can play a role in a promising catalyst design strategy for sustainable CO production.