Theoretical screening of P-block single atoms anchored on g-C3N4 for NO reduction to NH3

Abstract

The NO reduction reaction (NORR) is considered an attractive strategy for efficient NO removal and sustainable ammonia (NH₃) production. Herein, the catalytic behaviour of eleven p-block single atoms anchored on g-C₃N₄ monolayer (SAC@g-C₃N₄, SACB, Al, Si, Ga, Ge, As, In, Sn, Sb, Te and Bi) is systematically investigated as NORR electrocatalysts using density functional theory (DFT) calculations. The thermodynamic stability of SAC@g-C₃N₄ and its suppression of hydrogen evolution were examined. In addition, the thermodynamically favourable reaction pathway was identified based on the Gibbs free energy change, where B@g-C₃N₄ catalyst exhibited a low limiting potential (U_L) of −0.02 V. Furthermore, charge density analysis and projected density of states (PDOS) revealed the origin of NO activation. This work screens pure p-block SAC@g-C₃N₄ for the NORR and provides an atomic-level understanding of the reaction mechanism. These findings would aid the novel design of NORR catalysts and provide theoretical insights for the experimental synthesis of high-performance electrocatalysts.