Selective and Stable CO₂ Electroreduction to CH₄ via Electronic Metal-Support Interaction upon...

The CO₂ electroreduction to fuels is a feasible approach to provide renewable energy sources. Therefore, it is necessary to conduct experimental and theoretical investigations on various catalyst design strategies, such as electronic metal-support interaction, to improve the catalytic selectivity. Here a solvent-free synthesis method is reported to prepare a copper (Cu)-based metal-organic framework (MOF) as the precursor. Upon electrochemical CO₂ reduction in aqueous electrolyte, it undergoes in situ decomposition/redeposition processes to form abundant interfaces between Cu nanoparticles and amorphous carbon supports. This Cu/C catalyst favors the selective and stable production of CH₄ with a Faradaic efficiency of ≈55% at -1.4 V versus reversible hydrogen electrode (RHE) for 12.5 h. The density functional theory calculation reveals the crucial role of interfacial sites between Cu and amorphous carbon support in stabilizing the key intermediates for CO₂ reduction to CH₄ . The adsorption of COOH* and CHO* at the Cu/C interface is up to 0.86 eV stronger than that on Cu(111), thus promoting the formation of CH₄ . Therefore, it is envisioned that the strategy of regulating electronic metal-support interaction can improve the selectivity and stability of catalyst toward a specific product upon electrochemical CO₂ reduction.