Bimetal anchoring porous <scp>MXene</scp> nanosheets for driving tandem catalytic high‐efficiency electrochemical nitrate reduction

Abstract Electrochemical nitrate reduction reaction (NO 3 RR) is considered a promising strategy for ammonia synthesis and nitrate removal, in which catalyst development is crucial. Herein, a series of bimetal (Co and Cu) anchoring porous MXene nanosheets (Co x Cu y @PM) catalysts were prepared by combining etching and reduction strategy. On the one hand, Cu and Co bimetals provided tandem catalytic active sites for NO 3 RR. On the other hand, the in‐plane PM exhibited good electrical conductivity and multiple transport pathways. Consequently, the optimized Co 7 Cu 3 @PM catalyst achieved a high ammonia yield of 7.43 mg h −1 mg cat. −1 and an excellent Faraday efficiency (FE) of 95.9%. The mechanism of NO 3 RR was investigated by analyzing electrolysis products and in situ Fourier transform infrared spectroscopy. Furthermore, the Co 7 Cu 3 @PM based ZnNO 3 − battery exhibited the superior power density of 5.59 mW cm −2 and an NH 3 FE of 92.3%. This work presents an effective strategy to design MXene‐based high‐performance NO 3 RR electrocatalysts.