Nature-Inspired Design of Molybdenum-Selenium Dual-Single-Atom Electrocatalysts for CO2 Reduction

Electrochemical CO2 reduction (ECR) is becoming an increasingly important technology for achieving carbon neutrality. Inspired by the structure of naturally occurring Mo-dependent enzymes capable of activating CO2, a heteronuclear Mo-Se dual-single-atom electrocatalyst (MoSA-SeSA) for ECR into CO with a Faradaic efficiency of above 90% over a broad potential window from -0.4 to -1.0 V versus reversible hydrogen electrode is demonstrated here. Both operando characterization and theoretical simulation results verify that MoSA acts as central atoms that directly interact with the ECR feedstock and intermediates, whereas the SeSA adjacent to MoSA modulates the electronic structure of MoSA through long-range electron delocalization for inhibiting MoSA poisoning caused by strong CO adsorption. In addition, the SeSAs far from MoSA help suppress the competing hydrogen evolution side reaction and accelerate the CO2 transport by repelling H2O. This work provides new insight into the precise regulation and in-depth understanding of multisite synergistic catalysis at the atomic scale.

Automated summary

This study demonstrates a new heteronuclear Mo-Se single atom electrocatalyst (MoSA-SeSA) that can efficiently reduce CO2 to CO with high Faradaic efficiency. Both experimental and theoretical results indicate that MoSA interacts directly with the ECR feedstock and intermediates, while SeSA modulates the electronic structure of MoSA through long-range electron delocalization, inhibiting MoSA poisoning caused by CO adsorption. In addition, SeSA located far from MoSA helps suppress the hydrogen evolution reaction and facilitate CO2 transport.