Modulating CO2 Reduction Selectivity over Multi-Metal Electrocatalysts Derived from 0D Alloyed Halide Perovskite Crystals

Achieving efficient selectivity and precise control in synthesis of multi-metal catalysts for electroreduction of CO₂ to value-added feedstocks remains a significant challenge. The key to enhancing selectivity lies in improving the adsorption energy of intermediates, which mainly depends on electronic properties of electrocatalysts. By leveraging the electronegativity offset effect, we have integrated multiple metals into 0D hybrid perovskite crystals with precise compositions as promising precursors for multi-metal or high-entropy electrocatalysts. This strategy not only facilitates adjustments to the electronic distribution within matrix materials and enhances intermediate adsorption energies but also enables controllable synthesis of multicomponent catalyst systems. For electrochemical CO₂ reduction demonstration, the prototype multi-metal electrocatalysts CuBi_xIn_1-x derived from (C₈H₂₀N)₄In_1−xBi_xCuCl₉ crystals demonstrate tunable selectivity towards HCOO⁻ and CO, achieving Faradaic Efficiency (FE) values of 94% at −1.0 V vs. RHE for HCOO⁻ and 83% at −0.6 V vs. RHE for CO, alongside remarkable stability over 70 h. This can be contributed to the tunable electronic properties, which enhanced adsorption energies for intermediate and reduced Gibbs free energy associated with formation of formate and CO. The current study introduces an innovative crystal-derived catalyst-on-demand strategy aimed at enhancing efficient energy conversion.