Transition-Metal Borides (MBenes) as New High-Efficiency Catalysts for Nitric Oxide Electroreduction to Ammonia by a...

Here, the authors performed density functional theory calculations to study the catalytic performance of the nitric oxide reduction reaction (NORR) via a series of transition metal borides (MBenes). This work screened the M₂ B₂ type MBenes from the IVB to V transition metals from the periodic table and systematically probed the catalytic activity and selectivity for the NORR process. It has been reported that Fe₂ B₂ , Mn₂ B₂ , and Rh₂ B₂ can be high-performance catalysts for converting NO to NH₃ with smaller limiting potentials than other MBenes, and Nb₂ B₂ and Hf₂ B₂ have low limiting potentials of -0.11 V and -0.17 V for the NO production of NH₃ . The binding energy of ΔG*N can be a good descriptor of catalytic performance and is determined by the volcano plot of the rate-determining step. The reaction mechanisms for NO reduction to NH₃ , N₂ , and N₂ O have been studied in detail, atomic *N can interact with another *N or one *NO molecule to form N₂ and N₂ O via two successive hydrogenations. In this regard, *NO hydrogenation to *NOH has a lower formation energy than *HNO, and the MBenes have high selectivity for promoting the NORR and suppressing the hydrogen evolution reaction competition process.