Screening single/dual-atom oxidation of ammonia electrocatalysts on sulfur functionalized MXene: A first-principles approach

Abstract

The electrocatalytic oxidation of ammonia presents a promising avenue for sustainable energy and efficient waste ammonia treatment. Through extensive density functional theory calculations, we investigated the stability and ammonia oxidation performance of Sc, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn adsorbed onto Ti3C2S2, in both single and dual atom configurations. We revealed that Sc-Ti3C2S2 and Sc/Zn-Ti3C2S2 exhibit superior thermodynamic stability compared to other SACs/DACs explored in this study. Furthermore, the second metal promoter enhances the catalytic performance of ammonia oxidation, operating under the N + N mechanism. Utilizing a Sabatier analysis, we observed that Sc/Zn-Ti3C2S2 favors the Gerischer-Mauerer (G-M) mechanism over the N + N mechanism, with an onset potential at 0.98 V. In light of these findings, we propose that dual atom-promoted MXene can be a potentially outstanding catalyst for ammonia oxidation.