Simultaneous electrosynthesis of nitrate and hydrogen by integrating ammonia oxidation and water reduction

Abstract

Electrosynthesis of nitrate powered by renewable energy sources under mild conditions is an attractive alternative to the Oswald process for avoiding consuming large amounts of fossil fuels and eliminating associated greenhouse gas emissions. Here, we present an energy-saving and environmentally friendly strategy for efficient electrosynthesis of nitrate from ammonia oxidation by integrating hydrogen production from water reduction. We design a superior stable CuO nanosheet array catalyst and realize a total NOx– Faradaic efficiency of 98.7% via ammonia oxidation reaction (AOR) in an aqueous electrolyte. Hydrogen generation with a high Faradaic efficiency of 97.7% at the cathodic side is a concomitant AOR process. 0.2 mol L–1 NOx– can be produced after a long-term stability testing for 108 h, suggesting a potential practical application in decentralized nitrate and green hydrogen production.