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

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+. [Display omitted] •CO2 reduction to C3+ products over bimetallic systems is performed theoretically•CH2–C1 coupling is identified as the potential rate-limiting step•Tuning the carbon monoxide coverage can promote C3+ product generation•Optimizing the palladium/gold surface ratio can lower the activation barrier for C–C coupling Xu et al. investigate carbon dioxide electroreduction to C3+ products over bimetallic interfaces. They identify key intermediates and rate-limiting steps, ultimately indicating how tuning the bimetallic interface and surface coverage can lead to optimized C3+ chemical generation.