In‐Situ Characterization Technologies for Electrocatalytic Reduction nitrate to Ammonia on Copper‐Based Catalysts

Abstract

The excess nitrate (NO3‐) in the water mainly comes from agricultural fertilization and industrial wastewater, which breaks the nitrogen balance and poses a serious threat to the environment and human health. Driven by renewable energy, the electrocatalytic reduction of NO3‐ to ammonia (NH3) (ENO3RA) is an environmentally friendly and sustainable technology. Due to its special structure, copper (Cu) is currently one of the best catalysts for ENO3RA, but the reaction mechanism and the structure‐activity relationships of catalysts are still not clear enough. In‐situ characterization is a powerful tool to gain insight into the reaction process. This review introduces several types of in‐situ techniques such as in‐situ XAS, in‐situ FTIR and in‐situ DEMS, summarizes five pathways for converting *NO as the key intermediate to NH3 during ENO3RA on Cu‐based catalysts. The research progress of Cu‐based electrocatalysts in recent years is sorted out from the aspects of composition and structure, and the catalytic mechanisms were discussed with the help of in‐situ characterization technologies. This review would be of help to provide reference characterization methods for exploring the mechanism and the design of electrocatalysts for ENO3RA.