Copper-Based Electrocatalysts for Nitrate Reduction to Ammonia.

Ammonia (NH 3 ) is a highly important industrial chemical used as fuel and fertilizer. The industrial synthesis of NH 3 relies heavily on the Haber-Bosch route, which accounts for roughly 1.2% of global annual CO 2 emissions. As an alternative route, the electrosynthesis of NH 3 from nitrate anion (NO 3 - ) reduction (NO 3 - RR) has drawn increasing attention, since NO 3 - RR from wastewater to produce NH 3 can not only recycle waste into treasure but also alleviate the adverse effects of excessive NO 3 - contamination in the environment. This review presents contemporary views on the state of the art in electrocatalytic NO 3 - reduction over Cu-based nanostructured materials, discusses the merits of electrocatalytic performance, and summarizes current advances in the exploration of this technology using different strategies for nanostructured-material modification. The electrocatalytic mechanism of nitrate reduction is also reviewed here, especially with regard to copper-based catalysts.