A bioinspired sulfur-surrounded iron catalyst for ammonia synthesis

A nitrogenase-inspired inorganic compound consisting of iron (Fe) and molybdenum disulfide (MoS2) is designed with a promising capability of N2 fixation using first principles. Three Fe atoms are anchored on MoS2 to construct an Fe3S3 cluster, which resembles the active component of the FeMo-cofactor in nitrogenase. This similarity is evidenced not only in the geometric configuration of the two structures but also in their electronic properties. In the process of N2 fixation, the Fe and S moieties function as electron reservoir and buffer, respectively. The N2 activation mechanism and a reaction network for NH3 synthesis are elaborately investigated. The reaction pathway of N2 alternative hydrogenation involving *NHNH2 to *NH/*NH3 is more favorable than N2 distal hydrogenation. Further microkinetic modeling simulations show that the optimal reaction route has a high turnover frequency of 4.4 x 10-4 site-1 s-1 under the typical Haber-Bosch process reaction conditions. The development of this novel biomimetic catalyst presents a promising avenue for environmentally sustainable and high-performance catalyst design for ammonia synthesis. A nitrogenase-inspired inorganic compound consisting of iron (Fe) and molybdenum disulfide (MoS2) is designed with a promising capability of N2 fixation using first principles.