Boron-doped InSe monolayer as a promising electrocatalyst for nitrogen reduction into ammonia at ambient conditions

Nitrogen reduction reaction (NRR) for ammonia synthesis under mild conditions is promising but remains big challenge. Here, by the DFT method, we investigate the electrocatalytic NRR of boron-doped InSe (B-InSe) monolayer, which is expected to benefit from both the empty orbital of B ion and the favorable carrier mobility of InSe substrate. DFT calculations reveal that this marriage endows B-InSe with excellent electrocatalytic activity to reduce N-2 into NH3 under ambient conditions. B-InSe attracts N-2 and H strongly around B catalytic center, while presents unstable adsorptions on other surface sites, hence the competing hydrogen evolution reaction (HER) can be well avoided. As N-2 is adsorbed, B ion exchanges electrons with N-2 by the acceptance-donation pattern. Interestingly, the three In ions which nearest to B ion can offer assistance to denote electrons to N-2. In the following hydrogenation steps, this B-In-3 moiety plays role of reaction generator, while InSe substrate acts as electron reservoir. The NRR is performed along favorite distal pathway with low overpotential of 0.50 V, and the hydrogenation can be proceeded spontaneously except the steps of *N-NH2 and *NH3 show free energy uphill. These results indicate that B-InSe monolayer offers a new opportunity for efficient electrocatalyst for NRR.