Spatially Decoupled Cu Single Atoms and Nanoclusters Enabling Tandem Electrocatalytic Acetylene-to-Ethylene

High-load and high-dispersion strategies are an effective way to compensate for the inherent lack of activity of non-precious metals. However, high-load and high-dispersion catalysts are limited by the entropy increase principle and are not only difficult to prepare but also difficult to establish structure–performance relationships in heterogeneous catalytic systems. Here, we report Cu–Cux/MOF-200 catalysts for electrochemical acetylene selective hydrogenation (EASH) featuring high-load and high-dispersion synergistic Cu single atoms (SAs) and nanocluster sites (NCs). Experimental and theoretical calculations show the reactants H2O and C2H2 compete for adsorption at Cu NC/NP sites, while the efficient dual-site synergistic effect compensates for the difficulties in C2H2 activation and insufficient hydrogen ion supply under high current density. The electron-deficient Cu SAs weaken the energy barrier for H2O dissociation, while a linear relationship exists between particle size and valence state of Cu active sites for acetylene activation. Finally, the Cu–Cux/MOF-200 catalysts show no signs of deactivation after 51 h of long-term evaluation in an ethylene-rich atmosphere, achieving acetylene conversion exceeding 99.9% and ethylene selectivity exceeding 90%.