Hierarchical defective palladium-silver alloy nanosheets for ethanol electrooxidation

[Display omitted] •Hierarchical defective PdAg alloy nanosheets are successfully synthesized.•Moderate molar ratio of Pd/Ag precursors is critical to realizing the architecture.•Pd7Ag3 NS/C shows 8.8 times higher peak current density than Pd NS/C for EOR.•Pd7Ag3 NS/C exhibits better stability compared to Pd NS/C toward EOR.•The improvements come from the combined electronic and structural effects. Tuning the chemical composition and surface structure of electrodes is demonstrated as a feasible and effective strategy to tailor advanced catalysts for energy electrocatalysis. In this work, hierarchical palladium-silver alloy nanosheets (PdAg NS) with the thickness ~7 atoms and rich atomic defects are successfully prepared, using the carbon monoxide (CO) confinement approach. The optimized Pd7Ag3 NS/C exhibits 8.8 times higher catalytic peak current density and much better stability toward ethanol electrooxidation than Pd NS/C catalyst. The catalytic enhancement mechanism could be attributed to the synergetic effects among optimized electronic structure of Pd, novel architecture, and rich atomic defects.