Electrocatalytic Nitrogen Reduction by Transition Metal Single-Atom Catalysts on Polymeric Carbon Nitride
Mei Zheng, Hongbin Xu, Yi Li, Kaining Ding, Yongfan Zhang, Chenghua Sun, Wenkai Chen, Wei Lin
Abstract
Compared with the traditional Haber–Bosch process, electrocatalytic N2 reduction reaction (eNRR) is a promising strategy for ammonia production due to its eco-friendly and energy-saving process. Herein, the feasibility of transition metal (TM) atoms supported on melon-based carbon nitride (melon) for eNRR was systematically studied by the first-principles calculations, where melon is considered as the most popular polymeric carbon nitride (PCN) synthesized through the traditional thermally induced polymerization process. The results reveal that the single Mo, Ti, or V atom anchored on melon (Mo/melon, Ti/melon, or V/melon) exhibits an excellent eNRR catalytic activity, with low limiting potential (−0.36 V for Mo/melon and Ti/melon and −0.40 V for V/melon) and high selectivity toward the eNRR, due to the positive charge and concentrated spin polarization on the Mo, Ti, or V atom as well as moderate adsorption strength of eNRR intermediates. More importantly, the NH3 desorption is extremely energetically favorable for Mo/melon (0.26 eV) and V/melon (0.31 eV), endowing their outstanding durability for eNRR. Our study designed and screened the single-atom eNRR catalysts, which not only provides theoretical insight for the experiments but also endows with an alternative method for the sustainable synthesis of ammonia.