Regulation of Cu-MOF reconstruction for enhanced CO2 electroreduction

Cu-based catalysts are among the most promising materials for electrocatalytic CO2 reduction (CO2RR) to produce C2+ products. However, their practical application remains limited due to the uncontrollable structural reconstruction under operating conditions, leading to diminished selectivity. In this study, we propose a design strategy to regulate the reconstruction of Cu-based metal-organic framework (MOF) via doping Pd, which generate more efficient active sites and change the reaction pathways. The doped Pd with high oxygen affinity increases the dissociation energy barrier of Cu-O4 nodes, allowing MOF to reconstruct into Cu/Cu2O heterostructure with Pd single-atoms (Pd SA-Cu/Cu2O). This strategy also optimizes the adsorption of key intermediates, switching the main product from C1 to the C2+ product. Pd SA-Cu/Cu2O exhibits more than five times the Faradaic efficiency of C2+ products at-400 mA cm-2 than Cu(111)-enriched Cu. In-depth mechanistic analyses suggest that the switch of the reaction pathway towards C2+ products is attributed to the enhanced adsorption and asymmetric coupling of *CO and *CHO on Pd SA-Cu/Cu2O. Our approach offers valuable insights for understanding and regulation of the reconstruction and activity of Cu-based catalysts in the field of CO2RR.