Advertisement

Mechanistic Insight into Catalytic Oxidation of Ammonia on Clean, O- and OH-Assisted Ir(1 1 1) Surfaces

Authors

  • Dr. Xiaoqing Lu,

    Corresponding author
    1. College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363
    • College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363

    Search for more papers by this author
  • Zhigang Deng,

    1. College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363
    Search for more papers by this author
  • Ka-Shing Chau,

    1. Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (PR China)
    Search for more papers by this author
  • Longfei Li,

    1. College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363
    Search for more papers by this author
  • Zengqiang Wen,

    1. College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363
    Search for more papers by this author
  • Prof. Dr. Wenyue Guo,

    Corresponding author
    1. College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363
    • College of Science, China University of Petroleum, Qingdao, Shandong 266580 (PR China), Fax: (+86) 532-8698-3363

    Search for more papers by this author
  • Prof. Dr. Chi-Man Lawrence Wu

    1. Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (PR China)
    Search for more papers by this author

Abstract

Periodic DFT calculations have been performed to systematically investigate the catalytic mechanisms of ammonia (NH3) decomposition on clean, O- and OH-assisted Ir(1 1 1) surfaces. The adsorption configurations, reaction energies and barriers, and elementary steps were elaborated. Our results show that the NHx (x=1–3) decomposition prefers to proceed by means of the O- and OH-assisted reaction mechanisms, NH3+O→NH2+OH, NH2+OH→NH+H2O, and NH+OH→N+H2O, rather than the direct NHx decomposition of NH3→NH2→NH→N as a result of the high energy barriers involved. The promotion effect of the O- and OH-oxidizing agents are then discussed using energy barrier analysis. The relationships between the selectivity toward the final product and coverage, O to N coverage, and reaction temperature are elucidated. Finally, we compare our results with analogous investigations of NH3 decomposition on Pt, Rh, and Ir surfaces.

Ancillary