Ammonia (NH3) production from electrochemical nitrogen (N2) reduction reaction (NRR) under ambient conditions represents a sustainable alternative to the traditional Haber-Bosch process. However, the conventional electrocatalytic NRR process often suffers from low selectivity (competition with the hydrogen evolution reaction (HER)) and electron transfer bottleneck for efficient activation and dissociation. Herein, a strategy to simultaneously promote selectivity and activity through dual-incorporation of Se and O elements onto the shell of HER-inactive Te nanorods is reported. It is theoretically and experimentally verified that the exposure of lone-pair electrons in the TeO2 shell of Se, O dual-doped Te nanorods can maximize orbits overlap between N2 and Te for N-N bond activation via π-backdonation interactions. Further, the Gibbs free energy change indicates that the Lewis-basic anchor -SeO ligand with strong electron-donating characteristics serves as an electron reservoir and is capable of buffering the oxidation state variation of Te, thereby improving the thermodynamics of desorption of the intermediates in the N2-to-NH3 conversion process. As expected, a high faradaic efficiency of 24.56% and NH3 yield rate of ≈21.54 µg h-1 mg-1 are obtained under a low overpotential of ≈0.30 V versus reversible hydrogen electrode in an aqueous electrolyte under ambient conditions.
Keywords: bond activation; charge reservoir; electrocatalytic nitrogen reduction reaction (NRR); incorporation; tellurium.
© 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.