Theoretical investigation of dinitrogen to ammonia by Fe single atoms anchored on B/N-doped graphyne catalysts

Abstract

Forced by the pressure of energy and environment, the realization of nitrogen reduction to synthesize ammonia under mild conditions has become a hot topic of research. Here by means of first principle computations, we systematically researched Fe single atoms anchored on B/N-doped graphyne catalysts. It was found that the formation energies of B and N dopants were 1.1284 and − 0.2505 eV, the binding energies of Fe atom were − 6.0695, −3.1507 and − 6.2978 eV in Fe/GY, Fe/B-GY and Fe/N-GY, respectively, indicating facile experimental synthesis. As B atom introduced in graphyne, an unpaired p electron in a sp-hybridized C atom appeared due to sphybridized B and C atoms, and the adsorption of N2 molecule on Fe/B-GY was strongest for the d-p interaction, which was also verified by the evident electron transfer between single Fe atom and N2 molecular. In this catalyst system, Fe/B-GY showed higher catalytic ability with the minimum ΔG⁎N-NH of 0.41 eV, and the competitive HER was inhibited with ΔGH⁎ of −4.5272 eV. This work provides a new research idea for the design and construction of efficient single metal atoms embedded in a two-dimensional material substrate for the synthesis of ammonia under mild conditions.