Single and dual atom catalysts for nitrate reduction from metal tuning to performance descriptors

Abstract

Ammonia is a leading chemical in the agriculture, industry, and energy sectors, whereas nitrates are undesirable pollutants with harmful effects on the environment. Nitrate reduction to ammonia offers an efficient and sustainable route to produce green ammonia from waste nitrates. In this context, single- and dual-atom catalysts are considered the most promising owing to their maximum atomic utilization, highly tunable electronic structure, and well-defined active sites. This review focuses on the mechanism of nitrate reduction on single- and dual-atom catalysts, critically discussing the choice of metal, the engineering of coordination environment, and the effects of heteroatom doping. It also elaborates key performance descriptors and relates them to catalyst structure; the influence of operating parameters is also shown to be critical in determining catalytic activity and selectivity. The review further discusses how density functional theory and computational studies aid in the design and understanding of the operation of such catalysts. Finally, challenges and future research directions are elaborated to set a roadmap for researchers in the field.

Keywords

Single atom catalysts / dual atom catalysts / nitrate electroreduction / ammonia production

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