Promoted Electrochemical Ammonia Synthesis from Nitrate at the Ag–Cu Biphasic Interface
Xinyang Gao, Chenyuan Zhu, Chunlei Yang, Guoshuai Shi, Qinshang Xu, Liming Zhang
Abstract
Electrochemical nitrate reduction (NO 3 – R) presents a promising pathway for carbon-neutral ammonia (NH 3 ) synthesis. Enhancing NH 3 selectivity through a tandem process can be achieved by combining Cu with a secondary metal, which allows for an adjustable binding energy between the bimetallic catalyst and key nitrogen intermediates. Herein, we developed a biphasic Ag–Cu heterostructure with a controllable elemental composition, which significantly improved NH 3 production through tandem NO 3 – R. In-situ infrared spectroscopy and finite element simulations revealed that Ag serves as the active site for converting NO 3 – to NO 2 –, leading to a high localized concentration of NO 2 –, which is subsequently reduced to NH 3 on adjacent Cu sites. Density functional theory calculations further confirmed the critical role of the Ag–Cu biphasic interface in promoting tandem NH 3 production. This work offers valuable insights into the tandem NO 3 – R pathway in bimetallic heterostructures, providing a foundation for optimizing catalysts and advancing large-scale sustainable NH 3 synthesis.