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

Electrochemical reduction of nitrate to ammonia (NORR) offers a promising strategy for renewable ammonia (NH) synthesis and wastewater treatment, but still suffers from limited activity and NH selectivity due to the lack of effective electrocatalyst. Here, we perform a four-steps screening strategy to screen high performance NORR catalyst by density functional theory calculations using 23 single transition metals atom doped on 1T-WS/graphene (TM@1T-WS/graphene) as candidates. The results show that Cu@1T-WS/graphene exhibits the highest NORR performance 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 NORR catalysts. Moreover, the Cu@1T-WS/graphene also possesses excellent NH selectivity by suppressing competing hydrogen evolution reaction. This work provides a new avenue for the design of effective electrocatalysts for NORR.