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• Bioinspired Mo tape-porphyrin exhibits high catalytic NRR activity. • The novel NRR catalyst is designed and easy to synthesize experimentally. • Selectivity and durability of Mo tape-porphyrin. The efficient N 2 fixation to NH 3 in the biological system benefits from the electron transfer and catalysis of nitrogenase under ambient conditions, where N 2 reduction occurs at Mo and Fe sites. Herein, the electrochemical N 2 reduction reaction (NRR) on bioinspired Mo tape-porphyrin (denoted as MoP) has been systematically investigated on the basis of first-principles calculations. The anchoring of Mo atom to the biomolecular porphyrin changes the charge distribution and activates more delocalized π electrons in the fully conjugated π-system. The results reveal that N 2 favourably coordinated with Mo atom in end-on configuration and the electronic and magnetic properties of MoP are changed. The most promising reaction pathway for NRR on MoP is via the distal route with overpotential of 0.22 V. The excellent conductivity, highly localized and spin-polarized Mo-4d states of MoP endow it preeminent NRR activity at room temperature. Furthermore, the competitive 2-electron hydrogen evolution reaction (HER) is sufficiently mitigated and circumvented during the NRR progress. The high symmetry of MoP enables a simple synthetic pathway. Our findings provide a ingenious strategy for catalytic N 2 reduction and a practical manufacturing method for designing efficient and selective electrocatalyst. [ABSTRACT FROM AUTHOR]

Developing metal-free electrocatalysts is vitally significant for oxygen molecule dissociation. Graphdiynes (GDY) doped with nonmetal atoms are designed and optimized as metal-free electrocatalysts, and their oxygen molecule dissociation catalytic performances are evaluated by density functional theory. The results of formation energies and cohesive energies reveal that the most favorable site for B, Si, P, S, As, Se and Te doping is the sp 2-C atom at benzene ring (X-b), the most preferred sites for N and O doping is the sp -C atom nearest benzene ring at the chain (X-1 GDY). The O 2 molecules are chemisorbed on B, N, O, Si, P, S-doped GDYs, the O O bonds increase from 1.23 Å to 1.39–1.57 Å. But, the O 2 dissociation activation barrier on B, O, Si, P, S-doped GDY monolayers is up to 1.31–4.01 eV, indicating that this reaction is difficult to occur at room temperature. The O 2 is physisorbed on As, Se and Te-doped GDY monolayers with a distance between O 2 and GDY planes of 2.40–2.77 Å. The N-doped GDY has a small dissociation activation barrier of 0.90 eV, which may be a metal-free catalyst. The calculations promote further application of heteroatom doped GDYs on oxygen reduction reaction and other reactions. Unlabelled Image • Si-b GDY is semiconducting, B-b GDY exhibits p-type doping, while other doped GDYs exhibit n-type doping. • B-b, N-1, O-1, Si-b, P-b, S-b doped GDYs GDYs and pristine GDY could increase the O-O bond from 1.23 to 1.39~1.57 Å. • The O 2 is physisorbed on As, Se and Te-doped GDY monolayers with a distance between the O 2 and GDY planes of 2.40~ 2.77 Å. • O 2 →O+O reaction is difficult to occur on doped GDY monolayers with the activation barrier is more than 0.90 eV. [ABSTRACT FROM AUTHOR]