Enhanced Electroreduction of Carbon Dioxide to Methanol Using Zinc Dendrites Pulse‐Deposited on Silver Foam

Abstract

The electrocatalytic CO₂ reduction reaction (CO₂ RR) can dynamise the carbon cycle by lowering anthropogenic CO₂ emissions and sustainably producing valuable fuels and chemical feedstocks. Methanol is arguably the most desirable C₁ product of CO₂ RR, although it typically forms in negligible amounts. In our search for efficient methanol-producing CO₂ RR catalysts, we have engineered Ag-Zn catalysts by pulse-depositing Zn dendrites onto Ag foams (PD-Zn/Ag foam). By themselves, Zn and Ag cannot effectively reduce CO₂ to CH₃ OH, while their alloys produce CH₃ OH with Faradaic efficiencies of approximately 1 %. Interestingly, with nanostructuring PD-Zn/Ag foam reduces CO₂ to CH₃ OH with Faradaic efficiency and current density values reaching as high as 10.5 % and -2.7 mA cm^-2 , respectively. Control experiments and DFT calculations pinpoint strained undercoordinated Zn atoms as the active sites for CO₂ RR to CH₃ OH in a reaction pathway mediated by adsorbed CO and formaldehyde. Surprisingly, the stability of the *CHO intermediate does not influence the activity.