The importance of atomic charge distributions of solid boron material in N2 electrochemical reduction

Searching for efficient metal-free electrocatalysts to convert N-2 into NH3 is very important and challenge in chemistry. Here, we have explored the potential application of the metal-free solid alpha-B(12 )using as a promising electrocatalyst for N-2 reduction reaction (NRR) through a first-principles investigation. We have firstly analysed the charge distributions of the atoms of alpha-B-12, and found it to be amphoteric. Therefore the gas phase N-2 molecule gains electrons from negatively charged atoms of alpha-B-12 to form strong interaction with catalyst surface. Further the adsorption of N-2 on (0 0 1) surface termination of alpha-B-12 provides evidence that the alpha-B-12 surface can efficiently activate N-2 via electron transfer from alpha-B-12 to N-2 moiety. Additionally, our calculation results of possible NRR mechanisms of N-2 absorbed on alpha-B-12 surface showcased that the enzymatic mechanism is the most feasible reaction pathway with a very low overpotential of 0.20 V. In all, the results indicate that the electron-deficient alpha-B-12 can effectively activate N-2 through devoting its electron to N-2 and alpha-B-12 can be used as an effective metal-free electrocatalyst for N-2 fixation.