Discovering Effective Descriptors for CO2 Electroreduction to Predict the Catalysts with Different Selectivity

Abstract

Electroreduction is a promising approach to transform CO2, a greenhouse gas, into valuable hydrocarbons and could help mitigate the global warming effect. However, the high overpotential associated with known catalysts prohibits the adoption of CO2 electroreduction at the industrial scale. Finding an efficient catalyst is the key to overcome this hurdle. Understanding the factors that influence activity and selectivity is an essential step in systematically searching for efficient catalysts, and effective descriptors can guide such a search. In this work, we propose two effective descriptors: the CO2/CO adsorption energy descriptor and the carbon monomer mobility descriptor. The former is a general descriptor for various CO2 reduction reactions with products like CO, HCOOH, and CH4/C2H4; the latter is specific for reductions leading to CH4/C2H4. We further use these descriptors to analyze a variety of alloy catalysts and identify which among these may perform best at the reduction of CO2 to different products.