Boosting electrocatalytic reduction of nitrogen to ammonia under ambient conditions by alloy engineering

Abstract

Electrochemical reduction of nitrogen to ammonia under ambient conditions is regarded as a potential approach to tackle the energy-intensive Haber–Bosch process. However, it usually suffers from extremely low ammonia yield and faradaic efficiency due to the lack of highly active and selective electrocatalysts. Herein, fusiform-like ruthenium–copper alloy nanosheets (RuCu-FNs) were prepared by alloy engineering and utilized for the electrocatalytic NRR under ambient conditions. A high FE of 7.2% and an NH₃ yield rate of 53.6 μg h⁻¹ mg_cat⁻¹ were achieved at −0.1 V vs. RHE, which were better than those of the corresponding non-metallic catalyst and most alloy catalysts. The superior performance was ascribed to the differentiated second catalytic site for achieving both effectively adsorptive activation of chemically inert N₂ and intermediate desorption from the catalyst surface. The source of NH₃ was also identified with isotopic labeling via a self-developed simple and economic pathway. We provided a feasible pathway for the rational design of electrocatalysts for artificial N₂ fixation.