The configuration of Au^δ+-ZrO₂^δ− species induced activation enhances electrocatalytic CO₂ to formate conversion

Electrochemical CO₂ conversion into value-added chemicals is a promising technology to solve the greenhouse effect and recycle chemical energy. However, the electrochemical CO₂ reduction reaction (e-CO₂RR) is seriously compromised by weak CO₂ adsorption and a rough CO₂ activation process based on the chemical inertness of the CO₂ molecule and the formed fragile metal–C/O bond. In this paper, we designed and fabricated Au particles embedded in ZrO₂. The configuration of Au particles being of positive charge and ZrO₂ with negative charge is induced and generated by metal–support interactions (MSIs). As a result, Au/ZrO₂@C presents a big difference in the CO₂ conversion compared with the known work, affording a formate yield of 112.5 μmol·cm⁻²·h⁻¹ at −1.1 V vs. reversible hydrogen electrode (RHE), and a max formate Faradaic efficiency of up to 94.1% at −0.9 V vs. RHE. This superior performance was attributed to the activated Au–ZrO₂ interface to form the Au^δ+ species. Both in-situ Fourier transform infrared (FTIR) spectroscopy and theoretical calculations show that the MSIs configuration can be inclined to the *OCO intermediate generation on Au^δ+ species activating CO₂ molecules and then accelerate the formation of the *OCHO intermediate in e-CO₂RR, thereby favoring the CO₂ conversion to formate.