Bimodal nanoporous Pd3Cu1 alloy with restrained hydrogen evolution for stable and high yield electrochemical nitrogen reduction

Abstract

Electrocatalytic nitrogen reduction reaction (NRR) under ambient temperature and pressure holds a great promise for NH3 production while it is still impeded by the low active site density and sluggish kinetics, leading to a low product yield rate. In this work, bimodal nanoporous PdCu alloys that have three-dimensional hierarchical interconnected porous network and tailored Pd/Cu atomic ratios are designed and used for electrocatalytic NRR with high NH3 yield rate at room temperature and atmosphere pressure. The Pd3Cu1 alloy that has large surface area for high active site density, bimodal porous structure for efficient reactant accessibility as well as desired electronic structure for restrained hydrogen evolution reaction exhibits a high NH3 yield rate of 39.9 μg h−1 mgcat−1, which is among the highest values for recently reported NRR electrocatalysts with high loading amount. Even at a low overpotential of − 0.15 V versus reversible hydrogen electrode (vs RHE), the alloy can still deliver a NRR yield rate of more than 10 μg h−1 mgcat−1. Moreover, structural integrity of the Pd3Cu1 alloy makes it a highly stable NRR electrocatalyst that keeps 100% of its original activity after 18 h operation, retaining its great potential for promising NRR electrocatalysis. The synergistic combination of bimodal nanoporous structure and alloy strategy could be used to design efficient catalysts for a wide range of reactions.