Facile Construction of CuFe‐Based Metal Phosphides for Synergistic NO <sub>x</sub> <sup>−</sup> Reduction to NH <sub>3</sub> and Zn‐Nitrite Batteries in Electrochemical Cell
G. H. Wang, Chuanjun Wang, Xinxin Tian, Qiang Li, Shenjie Liu, Xiuying Zhao, Geoffrey I. N. Waterhouse, Xin Zhao, Xiaoqing Lv, Jing Xu
Abstract
Abstract The electrocatalytic nitrite/nitrate reduction reaction (eNO 2 RR/eNO 3 RR) offer a promising route for green ammonia production. The development of low cost, highly selective and long‐lasting electrocatalysts for eNO 2 RR/eNO 3 RR is challenging. Herein, a method is presented for constructing Cu 3 P‐Fe 2 P heterostructures on iron foam (CuFe‐P/IF) that facilitates the effective conversion of NO 2 − and NO 3 − to NH 3 . At −0.1 and −0.2 V versus RHE (reversible hydrogen electrode), CuFe‐P/IF achieves a Faradaic efficiency (FE) for NH 3 production of 98.36% for eNO 2 RR and 72% for eNO 3 RR, while also demonstrating considerable stability across numerous cycles. The superior performance of CuFe‐P/IF catalyst is due tothe rich Cu 3 P‐Fe 2 P heterstuctures. Density functional theory calculations have shed light on the distinct roles that Cu 3 P and Fe 2 P play at different stages of the eNO 2 RR/eNO 3 RR processes. Fe 2 P is notably active in the early stages, engaging in the capture of NO 2 − /NO 3 − , O─H formation, and N─OH scission. Conversely, Cu 3 P becomes more dominant in the subsequent steps, which involve the formation of N─H bonds, elimination of OH * species, and desorption of the final products. Finally, a primary Zn‐NO 2 − battery is assembled using CuFe‐P/IF as the cathode catalyst, which exhibits a power density of 4.34 mW cm −2 and an impressive NH 3 FE of 96.59%.