Adjacent-Ligand Tuning of Atomically Precise Cu−Pd Sites Enables Efficient Methanol Electrooxidation with a CO-Free Pathway

Abstract

Whether the catalyst can realize the non-CO pathway is the key to greatly improve the catalytic activity and stability of methanol oxidation reaction (MOR). It is feasible to optimize the reaction path selectivity by modifying organic ligands and constructing single-atom systems. At the same time, heterogeneous metal nanosheets with atomic thickness have been shown to significantly enhance the catalytic activity of materials due to their ultra-high exposure of active sites and synergistic effects. Herein, we synthesize an ultra-thin heterogeneous alloy metallene with organic ligand-modified surface Cu single atom by one-pot wet chemical method, and further construct an efficient Cu−Pd active sites. The prepared octanoic acid ligand modified PdCu single-atom alloys metallene (SAA OA−Cu-Pdene) shows excellent catalytic activity and stability, with mass activity up to 5.64 A mg_Pd⁻¹ and electrochemical active surface area (ECSA) up to 160.39 m² g_Pd⁻¹. Structural characterization and in situ experiment jointly indicate that ligand modulation brings about charge transfer, and the accompanying rapid migration of OH⁻ greatly improves the selectivity of non-CO pathways while improving the catalytic activity. The results highlight the importance of adjacent-ligand regulation and provide a new strategy for the design of MOR catalysts with high selectivity of non-CO pathway.