Nanoporous Copper–Palladium-Based Catalyst for Electrocatalytic Nitrate-to-Ammonia Conversion
Yunqing Xu, Wence Xu, Zhonghui Gao, Yanqin Liang, Hui Jiang, Zhaoyang Li, Zhenduo Cui, Enzuo Liu, Lili Ma, Shengli Zhu
Abstract
Electrochemical nitrate reduction reaction (NO 3 RR) is a green and environmentally friendly process with great potential for sustainable nitrogen cycle management and ecofriendly ammonia production. Development of catalysts with high Faradaic efficiency (FE) and ammonia yield is still a challenge for the large-scale industrial application of the NO 3 RR. In this work, a self-supported nanoporous bimetallic Cu–Pd-based catalyst (np Cu–Pd@ZrCuAl) is prepared by dealloying and galvanic replacement. The np Cu–Pd@ZrCuAl catalyst exhibits excellent electrocatalytic performance for NO 3 RR. The introduction of a tiny amount of Pd effectively enhances the H 2 O dissociation to provide sufficient H atoms for NH 3 production, while suppressing the competitive hydrogen evolution reaction, leading to remarkable FE of 95% with a NH 3 yield rate of 21.46 mg h –1 cm –2 . Theoretical calculations show that the Cu/Pd heterostructure modifies the electronic structure of Cu, optimizes the adsorption behavior of the intermediates, and reduces the energy barrier of the rate-determining ammonia desorption step, leading to fast ammonia generation. This work provides a valuable strategy for the design and synthesis of electrocatalysts for the NO 3 RR via heterostructure construction.