Computational Design of Transition Metal Single-Atom Electrocatalysts on PtS for Efficient Nitrogen Reduction.

Electrocatalytic nitrogen reduction is promising to serve as a sustainable and environmentally friendly strategy to achieve ammonia production. Single-atom catalysts (SACs) hold great promise to convert N into NH because of the unique molecular catalysis property and ultrahigh atomic utilization ratio. Here, we demonstrate a universal computational design principle to assess the N reduction reaction (NRR) performance of SACs anchored on a monolayer PtS substrate (SACs-PtS). Our density functional theory simulations unveil that the barriers of the NRR limiting potential step on different SAC centers are observed to be linearly correlated to the integral of unoccupied d states (UDSs) of SACs. As a result, the Ru SAC-PtS catalyst with the largest number of UDSs exhibits a much lower barrier of the limiting step than those of other SACs-PtS catalysts and the Ru(0001) benchmark. Our work bridges the apparent NRR activity and intrinsic electronic structure of SAC centers and offers effective guidance to screen and design efficient SACs for the electrochemical NRR process.