Engineering bimetallic interfaces and revealing the mechanism for carbon dioxide electroreduction to C3+ liquid chemicals

Abstract

The reduction reaction of carbon dioxide (CO₂RR) to liquid C₃₊ chemicals is a potential net-zero carbon process that can increase local resiliency to power outages and fuel consumption. However, the mechanism and catalyst design rules to promote CO₂RR-to-C₃₊ are unknown. Engineering bimetallic interfaces (e.g., palladium/gold) to tune intermediate adsorption is promising for promoting C₃₊ formation. Our density functional theory calculations find that ∗CH₂ could be the key intermediate, and C₁–CH₂ coupling could be the rate-limiting step to generate C₃₊. High CO surface coverages can promote the bimetallic interfacial sites, lower the energetics of the C₁–CH₂ coupling step, and enhance C₃₊ formation. We further construct a volcano plot of C₁–CH₂ kinetics as a function of the binding strength of key intermediate ∗CH₂ via engineering the d-band center of the interfacial site. Our findings could guide the rational design of bimetallic interfaces and their near-surface microenvironment for enhancing CO₂RR-to-C₃₊.