Electrocatalytic nitrate reduction to ammonia (NRA) has been considered a highly promising method for "waste to treasure". Herein, a heterogeneous catalyst FeP/Cu3P/CF enriched with Lewis acid sites was designed for efficient NRA. The faradaic efficiency and NH3 yield are up to 95.61 % and 0.2573 mmol h-1 cm-2, the NH3-N selectivity is 95.11 %, and the NO3--N conversion is close to 100 %. Experimental and theoretical studies verify that the formation of the interface activates the originally inert Fe site and makes it become the second active center in addition to Cu. The charge transfer greatly raises the positive charge density of Feδ+ and Cuδ+ sites, leading to a significant increase in their Lewis acidity, which enables them to interact strongly with the Lewis base NO3- and improves the NRA performance; meanwhile, the ability of P site with increased negative charge density to capture H enhances, which is beneficial for the subsequent hydrogenation of nitrate reduction. This work provides an approach for designing efficient NRA catalysts through interface engineering strategy.
Keywords: Activation; FeP/Cu(3)P; Heterointerfaces; Lewis acidity; Nitrate reduction.
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