Electrocatalytic reduction of nitrate for ammonia production – Rational design of highly active catalysts

Abstract

Electrocatalytic reduction of nitrate (NO₃⁻RR) to ammonia can convert pollutant NO₃⁻ into value−added product ammonia, making it a meaningful technology for recycling of nitrogen element from wastewater. This review article analyzes the feasible industrial process of NO₃⁻RR, followed by a summary of the NO₃⁻RR mechanisms. Two important concerns in NO₃⁻RR to ammonia: whether to consider environmental ammonia pollution and the economic viability of the process, have been addressed. A statistical analysis of relevant catalysts reported since 2020 has been conducted. The strategies for rational design of highly active catalysts of NO₃⁻RR to ammonia are respectively discussed, including the exploration of metal elements with nature of high activity and NH₃ selectivity, regulation of NO₃⁻RR intermediates and H atom adsorption strength, increasing of active sites, and efficient screening of catalysts using descriptors. The review article concludes by outlining future prospects and challenges of NO₃⁻RR to ammonia.