Theoretical Design of a Single Cu Atom Supported on 1T-WS2/Graphene Catalyst for Electrocatalytic Nitrate Reduction to Ammonia.

Electrochemical reduction of nitrate to ammonia (NO3RR) offers a promising strategy for renewable ammonia (NH3) synthesis and wastewater treatment, but still suffers from limited activity and NH3 selectivity due to the lack of effective electrocatalyst. Here, we perform a four-steps screening strategy to screen high performance NO3RR catalyst by density functional theory calculations using 23 single transition metals atom doped on 1T-WS2/graphene (TM@1T-WS2/graphene) as candidates. The results show that Cu@1T-WS2/graphene exhibits the highest NO3RR activity among 23 candidates with a low rate determining step energy barrier of 0.12 eV, which is much lower than that of the most of recently reported NO3RR catalysts. Moreover, the Cu@1T-WS2/graphene also possesses excellent NH3 selectivity by suppressing competing hydrogen evolution reaction. This work provides a new avenue for the design of novel effective NO3RR catalysts for practical application.