Selective Electrochemical Conversion of Carbon Dioxide to Formic Acid on Oxide-Derived Sn_xZn Bimetallic Catalysts

The use of bimetallic catalysts for electrochemical CO2 reduction is considered a promising strategy to enhance the catalytic activity as well as the selectivity. Here, oxide-derived (OD) Sn-Zn bimetallic electrocatalysts are developed for the exclusive conversion of CO2 to HCOOH in an aqueous media. A pure Zn catalyst promotes conversion of CO2 to CO with a high Faradaic efficiency (FE) of 80%, whereas a Sn1Zn nanoporous catalyst drives an efficient CO2-to-HCOOH pathway with a high FEHCOOH of 80% at a moderate overpotential of -1.0 VRHE. The interaction between Sn and Zn plays an essential role in tuning the selectivity and catalytic activity. Sn-Zn bimetallic catalysts effectively localize electrons to metallic Sn, facilitating the selective and stable conversion of CO337397049_20220916095332725 / urn:si:17097159 to HCOOH. Additionally, the catalyst maintains its initial efficiency even after a long-term (18 h) CO2 reduction reaction. This study experimentally demonstrates that OD Sn-Zn bimetallic catalysts are efficient and stable for reducing the CO2 gas to HCOOH.