Heterostructured Pd/PdO nanowires for selective and efficient CO2 electroreduction to CO

Palladium (Pd) nanostructures are highly promising electrocatalysts for the carbon dioxide electrochemical reduction (CO2ER). At present, it is still challenge for the synthesis of Pd nanostructures with high activity, selectivity and stability. In this work, a facile PdII-complex pyrolysis method is applied to synthesize the high-quality one-dimensional heterostructured Pd/PdO nanowires (Pd/PdO H-NWs). The as-prepared Pd/PdO H-NWs have a large electrochemically active surface area, abundant defects and Pd/PdO heterostructure. Electrochemical measurement results reveal that Pd/PdO H-NWs exhibit up to 94% CO Faraday efficiency with a current density of 11.6 mA cm−2 at an applied potential of −0.8 V. Meanwhile, Pd/PdO H-NWs can achieve a stable catalytic process of 12 h for CO2ER. Such outstanding CO2ER performance of Pd/PdO H-NWs has also been verified in the flow cell test. The density functional theory calculations indicate that Pd/PdO heterostructure can significantly weaken the CO adsorption on Pd sites, which improves the CO tolerance and consequently enhances the catalytic performance of Pd/PdO H-NWs for CO2ER. This work highlights a facile complex pyrolysis strategy for the synthesis of Pd-based CO2ER catalysts and provides a new application instance of metal/metal oxide heterostructure in electrocatalysis.