Coupling Layered Spraying with Joule Heating to Achieve Efficient CuZn Alloy Synthesis for Self-Powered Nitrate Reduction to Ammonia

Abstract

Electrochemical reduction of nitrate to ammonia (NO₃RR) is an emerging and environmentally sustainable approach for synthesizing ammonia (NH₃). However, the electrocatalytic NO₃RR faces significant challenges of the slow kinetics of active hydrogen (*H) transfer and extreme dependence on conventional energy sources. Herein, we innovatively propose a novel strategy of layered spraying coupled with a Joule heating strategy to prepare a CuZn₅ alloy for enhancing the adsorption energy of *H and reducing the desorption energy of NH₃, which is guided by density functional theory (DFT) calculations. The synthesized CuZn₅ alloy exhibits exceptional performance, with a remarkable NH₃ Faradaic efficiency reaching 98.4% and an impressive yield rate of 420 μmol h⁻¹ cm⁻². Furthermore, the CuZn₅ catalyst is integrated into a self-powered NO₃RR system, which is powered by a high-performance triboelectric nanogenerator (I_max = 100 μA, V_max = 600 V), achieving an NH₃ yield rate of 54.70 μmol h⁻¹ cm⁻² without the external power source. This study presents a novel method for the efficient preparation of NO₃RR catalysts and offers a clean energy solution for the production of high-value chemicals.