Atomic Co―P Catalytic Pair Drives Efficient Electrochemical Nitrate Reduction to Ammonia

Electrochemically reducing nitrate (NO3-), a common water pollutant, to valuable ammonia (NH3) offers a green, sustainable, and decentralized route for ammonia synthesis. Electrochemical nitrate reduction reaction (NO3-RR) involves two crucial reaction steps: nitrate deoxygenation followed by nitrite hydrogenation; in particular, the nitrite hydrogenation reaction is the rate-determining step (RDS) for NO3-RR. In this work, an atomically dispersed cobalt-phosphorus (CoP) catalytic pair (CP) with strong electronic coupling is reported. The Co site in CoP CP effectively activates NO3-, while the P site in CoP CP facilitates water dissociation to release H+, synergistically enhancing the thermodynamic and kinetic performance of electrochemical nitrate reduction to ammonia. CoP catalytic pair (CP) in Co1-P/NPG catalyst can efficiently catalyze NO3- reduction reaction (NO3-RR) to produce ammonia, in which the P site facilitates water dissociation to release H+ and the Co site effectively activates NO3-, accelerating the proton-coupled electron transfer (PCET) kinetics of NO3-RR. image