Work

Engineering vacancy and hydrophobicity of two-dimensional TaTe2 for efficient and stable electrocatalytic N2 reduction

Year: 2021

Type: article

Abstract: Demand for ammonia continues to increase to sustain the growing global population. The direct electrochemical N 2 reduction reaction (NRR) powered by renewable electricity offers a promising carbon-neutral and sustainable strategy for manufacturing NH 3 , yet achieving this remains a grand challenge. Here, we report a synergistic strategy to promote ambient NRR for ammonia production by tuning the Te vacancies (V Te ) and surface hydrophobicity of two-dimensional TaTe 2 nanosheets. Remarkable NH 3 faradic efficiency of up to 32.2% is attained at a mild overpotential, which is largely maintained even after 100 h of consecutive electrolysis. Isotopic labeling validates that the N atoms of formed NH 4 + originate from N 2 . In situ X-ray diffraction indicates preservation of the crystalline structure of TaTe 2 during NRR. Further density functional theory calculations reveal that the potential-determining step (PDS) is ∗NH 2 + (H + + e – ) → NH 3 on V Te -TaTe 2 compared with that of ∗ + N 2 + (H + + e – ) → ∗N–NH on TaTe 2 . We identify that the edge plane of TaTe 2 and V Te serve as the main active sites for NRR. The free energy change at PDS on V Te -TaTe 2 is comparable with the values at the top of the NRR volcano plots on various transition metal surfaces.

Source: The Innovation

DOI: 10.1016/j.xinn.2021.100190