Phosphorus-rich CoP₄@N-C nanoarrays for efficient nitrate-to-ammonia electroreduction

The electrochemical nitrate reduction reaction (NO₃^-RR) is a novel green method for ammonia synthesis. However, the lack of sufficient catalysts has hindered the development of the NO₃^-RR. This research develops a transformation of porous CoP@N-C/CC into porous phosphorus-rich CoP₄@N-C/CC through high-temperature calcination. Due to its unique phosphating-rich structure, CoP₄@N-C/CC exhibits an excellent Faraday efficiency (FE: 92.3%) and NH₃ yield (610.2 μmol h^-1 cm^-2). Such a catalyst with more P-P bonds can provide more active sites, effectively enhancing the adsorption and reaction processes of reactant molecules. In addition, the catalyst has good durability and catalytic stability, which provides a possibility for the future application of electrocatalytic ammonia production.