Computational Discovery of New C─C Coupling Electrocatalysts for CO₂ Electroreduction

Catalyst development is key in advancing low-temperature CO₂ electroreduction systems on the path to energy-efficient and low-carbon intensity fuels and chemicals. Much focus lies today on transition metals and their modification, yet a promising avenue remains unexplored-perovskite oxides. Owing to perovskite oxides' distinct electronic structures and reactivity patterns, the systematic screening of these materials can enable identification of new activity regimes and point to mechanisms and active sites distinct from those in traditional transition metal catalysts. Herein, a data-driven search is applied to evaluate the stability of a large library of ≈1500 ABO₃ perovskites at the relevant pH and electrode potentials of CO₂ electroreduction. This study identifies 31 stable candidates and chooses the ATaO₃ family of perovskites to synthesize and investigate for its electrochemical performance. Strikingly, C─C coupling is observed with a C₂ Faradaic Efficiency (FE) of 10% at 100 mAcm^-2 with KTaO₃. This study finds the size of the A element in ATaO₃ to be critical in C─C coupling, and computational reaction pathway analysis shows a CO^*─^*CHO coupling-driven mechanism for C₂ production. The findings in this study suggest routes to materials design for electrocatalytic C─C coupling on non-copper surfaces.