Two dimensional electrocatalysts engineering via heteroatom doping for electrocatalytic nitrogen reduction
Electrocatalytic N2 reduction reaction (eNRR) - which can occur under ambient conditions with renewable energy input - became a promising synthetic pathway for ammonia (NH3) and has attracted growing attention in the past few years. Some achievements have been made in eNRR, however there remain significant challenges to realize satisfactory NH3 production. Therefore, the rational design of highly efficient and durable eNRR catalyst with N≡N bond activating and wrecking ability is highly desirable. Two-dimensional (2D) materials have shown great potentials in electrocatalysis for energy conversion and storage. Although most 2D materials are inactive toward eNRR, they can be activated by various modification methods. Heteroatom doping engineering can impact charge distribution and spin states on catalytic sites, therefore accelerates the dinitrogen adsorption and protonation process. This review summarises the recent research progress of heteroatom-doped 2D materials, including carbon, molybdenum disulfide (MoS2) and metal carbides (MXenes), for eNRR. In addition, some existing opportunity and future research directions in electrocatalytic nitrogen fixation for ammonia production are discussed.