High-Entropy Metal\nSulfide Promises High-Performance\nCarbon Dioxide Reduction

The efficient conversion of carbon dioxide (CO<sub>2</sub>) requires\nthe development of stable catalysts with high selectivity and reactivity\nwithin a wide potential range. Here, the high-entropy metal sulfide\nCuAgZnSnS<sub>4</sub> is designed for CO<sub>2</sub> reduction with\nexcellent performance (FE<sub>carbon products</sub> ≥\n90%) in whole test potential windows (600 mV) based on the synergistic\neffect of the high-entropy metal sulfide. In particular, CuAgZnSnS<sub>4</sub> exhibits better single-product selectivity with the highest\nFE<sub>HCOOH</sub>/FE<sub>CO</sub> value (29.03) at −1.28 versus\nreversible hydrogen electrode (RHE). In combination with <i>in\nsitu</i> measurements and theoretical calculations, it is further\nrevealed that the synergistic effect of CuAgZnSnS<sub>4</sub> realizes\nthe controllable regulation of the surface electronic structure at\nSn active sites, strengthening orbital interactions between *OCHO\nand Sn active sites. As a result, the effective adsorption and activation\nof *OCHO instead of *H are obtained, improving the single-product\nselectivity of electrocatalytic CO<sub>2</sub> reduction and inhibiting\nthe competitive hydrogen evolution reaction significantly. Our findings\nmay complete the understanding of the synergistic effect for high-entropy\nmaterials in catalysis and offer new insight into the design of efficient\nelectrocatalysts with high catalytic activity.