A Mo–salicylaldehyde-linker (Mo–Tp) based 2D MOF as a single-atom catalyst for the nitrogen reduction reaction

Abstract

Two-dimensional (2D) materials for the electrocatalytic nitrogen reduction reaction (NRR) can offer a groundbreaking and sustainable alternative to the traditional Haber–Bosch process. Two-dimensional metal–organic frameworks (2D MOFs) have the potential to serve as single-atom catalysts (SACs), enabling the utilization of active metal centers up to 100% in the eNRR and also capable of reducing the HER effectively. This work outlines the screening of a new series of TM–Tp 2D MOFs (where Tp = 1,3,5-triformylphloroglucinol; TM = Cu, Ni, Cr, Mo, Os, Ru, and W) for the NRR, using density functional theory. Two screening stages based on the activation of the N₂ molecule and stabilization of the NNH intermediate showed that the Mo–Tp MOF monolayer is the most viable catalyst to be studied further. Mo–Tp shows outstanding stability and high potency towards being an efficient NRR catalyst with high selectivity. An investigation of the NRR pathway showed a limiting potential (U_L) of −0.38 V in the distal pathway. Furthermore, the theoretical faradaic efficiency (FE_t) is 100% towards the NRR. Our findings show that Mo-based 2D MOFs exhibit outstanding performance as NRR catalysts.