Abstract
Electrochemical NO reduction into NH3 addresses the need for harmful NO abatement and offers an attractive alternative to the industrial Haber–Bosch process, but it requires the development of advanced catalysts with high activity and selectivity toward NH3 synthesis. In this work, we report on our recent experimental findings that a MnO2 with oxygen vacancies (VO) nanowire array on Ti mesh (MnO2-x NA/TM) behaves as a high-active and stable electrocatalyst for ambient NO reduction to NH3. In 0.2 M Na2SO4, such catalyst shows a large NH3 yield of 27.51 × 10−10 mol s−1 cm−2 and a high Faradic efficiency of 82.8%, considerably outperforming the pristine MnO2 counterpart (8.83 × 10−10 mol s−1 cm−2, 44.8%). Density function theory calculations indicate that NO adsorption is enhanced on MnO2-x (211) surface due to stronger electronic interaction between NO and Mn atoms as a result of the VO.
center4699000A MnO2 with oxygen vacancies nanoarray on Ti mesh (MnO2-x NA/TM) is active for ambient NO-to-NH3 conversion, achieving a large NH3 yield of 27.51 × 10-10 mol s-1 cm-2 and a high Faradaic efficiency of 82.8% in 0.2 M Na2SO4. The catalytic mechanism is investigated by theoretical calculations. [Display omitted]
•MnO2-x nanowire array was used for NO reduction electrocatalysis.•MnO2-x nanowire array shows high NORR activity.•Oxygen vacancies enhance the electronic interaction between NO and Mn atoms.