Key Role of Local Chemistry in Lattice Nitrogen‐Participated N2‐to‐NH3 Electrocatalytic Cycle over Nitrides

Abstract

AbstractMetal nitrides offer great opportunities for improving activity and selectivity of electrocatalytic nitrogen reduction reaction (ENRR) via the lattice nitrogen‐participated mechanism. Understanding the role of local chemistry of lattice nitrogen is important for establishing rational design principles of nitride catalysts. Herein, high‐throughput theoretical calculations are employed to investigate lattice nitrogen‐participated ENRR over a family of antiperovskite nitrides (M′M3N, M and M′ are different metal atoms) with highly tunable surrounding environments of N atoms. The M′M3N structure comprises isolated N atoms in the center, M atoms in the first coordination shells, and M′ atoms in the second coordination shells. An appropriate M‐N bond strength is found to be crucial for designing ideal nitride catalysts. Specifically, weak M‐N bonding facilitates the participation of lattice nitrogen and better activity, but too weak M‐N bonding results in structural instability of antiperovskite. The type of M element governs M‐N bond strength through adjusting hybridization interactions between M orbital and N orbital, and the M′ element can further finely regulate M‐N bond strength via M‐M′ polarization effects. Finally, AgBa3N, AlBa3N, GaBa3N catalysts are screened to possess greater ENRR activity than the benchmarking Ru (0001) catalysts and high selectivity toward hydrogen evolution reaction.