Morphological and Compositional Design of Pd-Cu Bimetallic Nanocatalysts with Controllable Product Selectivity toward CO Electroreduction.

Electrochemical conversion of carbon dioxide (electrochemical reduction of carbon dioxide) to value-added products is a promising way to solve CO emission problems. This paper describes a facile one-pot approach to synthesize palladium-copper (Pd-Cu) bimetallic catalysts with different structures. Highly efficient performance and tunable product distributions are achieved due to a coordinative function of both enriched low-coordinated sites and composition effects. The concave rhombic dodecahedral Cu Pd (CRD-Cu Pd) decreases the onset potential for methane (CH ) by 200 mV and shows a sevenfold CH current density at -1.2 V (vs reversible hydrogen electrode) compared to Cu foil. The flower-like Pd Cu (FL-Pd Cu) exhibits high faradaic efficiency toward CO in a wide potential range from -0.7 to -1.3 V, and reaches a fourfold CO current density at -1.3 V compared to commercial Pd black. Tafel plots and density functional theory calculations suggest that both the introduction of high-index facets and alloying contribute to the enhanced CH current of CRD-Cu Pd, while the alloy effect is responsible for high CO selectivity of FL-Pd Cu.