Bimetal anchoring porous MXene nanosheets for driving tandem catalytic high‐efficiency electrochemical nitrate reduction

Electrochemical nitrate reduction reaction (NO3RR) 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 (CoxCuy@PM) catalysts were prepared by combining etching and reduction strategy. On the one hand, Cu and Co bimetals provided tandem catalytic active sites for NO3RR. On the other hand, the in‐plane PM exhibited good electrical conductivity and multiple transport pathways. Consequently, the optimized Co7Cu3@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 NO3RR was investigated by analyzing electrolysis products and in situ Fourier transform infrared spectroscopy. Furthermore, the Co7Cu3@PM based ZnNO3− battery exhibited the superior power density of 5.59 mW cm−2 and an NH3 FE of 92.3%. This work presents an effective strategy to design MXene‐based high‐performance NO3RR electrocatalysts.