Electrochemical Nitrogen Reduction Application of Atomically Dispersed Metallic Materials

Abstract

Currently, ammonia (NH3) is produced using the Haber–Bosch process on an industrial scale. However, this process is energy-intensive and depends on non-renewable energy sources. Besides, the Haber–Bosch process is labeled as a major source of greenhouse gas emissions, thus causing global warming. The electrochemical reduction of molecular dinitrogen to NH3 under ambient conditions, as an energy-efficient and environmentally benign process, has been known as a promising alternative to the Haber–Bosch process. In the last few years in this field, significant efforts have been made for improving the catalyst performance of nitrogen reduction reaction (NRR) in terms of enhancing NH3 yield and Faradic efficiency. Among myriad electrocatalysts, single-atom catalysts (SACs) have emerged as one type of the most promising NRR catalysts due to their atomically dispersed active sites, unique electronic structure, unsaturated coordination environment, and maximum atom utilization efficiency. All these unique properties of SACs have a profound effect on improving the NH3 yield and Faradic efficiency. In this chapter, we have summarized the most important strategies employed for the synthesis of SACs including impregnation and coprecipitation, spatial confinement, coordination sites attachment, defect engineering, ball milling, electrochemical deposition, and atom-trapping strategies. This chapter also covers various theoretical and experimental approaches employed to screen SACs for their potential application in electrocatalytic NRR. On this basis, we have also discussed the challenges opportunities and future research directions.