Efficient NO electroreduction via MoN2 based on Mars-van-Krevelen mechanism: a novel design approach.

CONTEXT: We theoretically demonstrated the possibility of reducing nitric oxide (NO) to ammonia via the Mars-van-Krevelen (MvK) reaction mechanism on MoN2. Simultaneously, a hydrogen passivation strategy was proposed to improve the catalytic performance of the nitric oxide reduction reaction (NORR) on MoN2. The results show that the catalytic performance at the 100% hydrogen passivation concentration is approximately 2.5 times as large as that of untreated MoN2. Our research may provide a feasible approach for further improving the performance of electrocatalysts for NORR based on the MvK reaction mechanism.

METHODS: With the help of DMol3, the Perdew-Burke-Ernzerhof (PBE) functional was utilized to calculate the exchange-correlation energy. The DFT semi-core pseudopotentials (DSPP) and double numerical plus polarization (DNP) numerical basis set were adopted to treat core electrons and atomic orbitals, respectively. The Hirshfeld population analysis was performed to describe the charge transfer. The electron density difference (EDD) and its local integral curve were utilized to analyze the changes in the electronic structure of the H passivation system. Meanwhile, ab initio molecule dynamics (AIMD) simulations were performed with the NVT ensemble to evaluate the structural stability on a short time scale.