High-Entropy Metal Sulfide Promises High-Performance Carbon Dioxide Reduction

The efficient conversion of carbon dioxide (CO₂) requires the development of stable catalysts with high selectivity and reactivity within a wide potential range. Here, the high-entropy metal sulfide CuAgZnSnS₄ is designed for CO₂ reduction with excellent performance (FE_{carbon products} ≥ 90%) in whole test potential windows (600 mV) based on the synergistic effect of the high-entropy metal sulfide. In particular, CuAgZnSnS₄ exhibits better single-product selectivity with the highest FE_HCOOH/FE_CO value (29.03) at -1.28 versus reversible hydrogen electrode (RHE). In combination with in situ measurements and theoretical calculations, it is further revealed that the synergistic effect of CuAgZnSnS₄ realizes the controllable regulation of the surface electronic structure at Sn active sites, strengthening orbital interactions between *OCHO and Sn active sites. As a result, the effective adsorption and activation of *OCHO instead of *H are obtained, improving the single-product selectivity of electrocatalytic CO₂ reduction and inhibiting the competitive hydrogen evolution reaction significantly. Our findings may complete the understanding of the synergistic effect for high-entropy materials in catalysis and offer new insight into the design of efficient electrocatalysts with high catalytic activity.