Amorphization activated FeB2 porous nanosheets enable efficient electrocatalytic N2 fixation

Designing active,robust and cost-effective catalysts for the nitrogen reduction reaction(NRR) is of paramount significance for sustainable electrochemical NH3 synthesis.Transition-metal diborides(TMB)have been recently theoretically predicted to be a new class of potential NRR catalysts,but direct experimental evidence is still lacking.Herein,we present the first experimental demonstration that amorphous FeBporous nanosheets(a-FeBPNSs) could be a highly efficient NRR catalyst,which exhibited an NH3 yield of 39.8 μg hmg(-0.3 V) and a Faradaic efficiency of 16.7%(-0.2 V),significantly outperforming their crystalline counterpart and most of existing NRR catalysts.First-principle calculations unveiled that the amorphization could induce the upraised d-band center of a-FeBto boost d-2π~* coupling between the active Fe site and ~*NH intermediate,resulting in enhanced ~*NH stabilization and reduced reaction barrier.Out study may facilitate the development and understanding of earth-abundant TMB-based catalysts for electrocatalytic Nfixation.