Catalytic photo-redox of simulated air into ammonia over bimetallic MOFs nanosheets with oxygen vacancies

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Wenjun Zhao
  • Jiangzhou Qin
  • Wei Teng
  • Jincheng Mu
  • Jun Ke
  • Baojun Liu
  • Shaobin Wang

Detail(s)

Original languageEnglish
Article number121046
Journal / PublicationApplied Catalysis B: Environmental
Volume305
Online published28 Dec 2021
Publication statusPublished - 15 May 2022

Abstract

Solar-driven conversion of nitrogen (N2) into ammonia (NH3) is a promising alternative to the Haber-Bosch process, while still suffers from low conversion efficiency due to inactive N[tbnd]N bond. Herein, a novel pathway of photocatalytic air redox reaction (ARR) to ammonia via NO is proposed and tested over an effective catalyst of oxygen-vacancy-rich bimetallic Cu-Co organic framework ultrathin nanosheets (OVR-CuCo-MOFs NS) under visible light. The catalyst with unique oxygen defective sites shows an excellent NH3 synthesis rate from air (287.76 ± 7.02 μmol g-1·h-1), which is 5.4-fold higher than that from pure N2. Moreover, experiments and theoretical calculations indicate that the transformation of air mainly follows a redox pathway, in which N2 and O2 can be trapped at the oxygen vacancies to generate nitric oxide (*NO) and further be reduced to ammonia by visible light. The ARR process shows a lower barrier of free energies in the onset activation step (*N2 → *N-NO, −0.08 eV) and rate-limiting step (*NO → *NHO, 1.23 eV) compared with those of traditional nitrogen reduction (*N2 → *N-NH, 1.48 eV and H2N-NH2 → *NH2, 1.29 eV, respectively). This work provides a new and sustainable pathway for photo-driven ammonia synthesis.

Research Area(s)

  • Air redox reaction (ARR), Ammonia photosynthesis, Bimetallic organic frameworks, Oxygen vacancies

Citation Format(s)

Catalytic photo-redox of simulated air into ammonia over bimetallic MOFs nanosheets with oxygen vacancies. / Zhao, Wenjun; Qin, Jiangzhou; Teng, Wei; Mu, Jincheng; Chen, Chang; Ke, Jun; Huang, Jacob C.; Liu, Baojun; Wang, Shaobin.

In: Applied Catalysis B: Environmental, Vol. 305, 121046, 15.05.2022.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review