Format

Send to

Choose Destination
See comment in PubMed Commons below
J Chem Phys. 2013 May 21;138(19):194701. doi: 10.1063/1.4804160.

Elementary steps of the catalytic NO(x) reduction with NH3: cluster studies on adsorbate diffusion and dehydrogenation at vanadium oxide substrate.

Author information

  • 1Inorg. Chem. Dept., Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.

Abstract

We discuss the details of important steps of the selective catalytic reduction (SCR) of NO(x) at model V2O5(010) substrate. First, diffusion processes at the substrate surface are considered where hydrogen and ammonium, NH4, are used as examples. Hydrogen diffusion, a prerequisite for water formation involving substrate oxygen, is described by diffusion paths between adjacent surface oxygen sites. Corresponding energy barriers are determined mainly by the flexibility and the amount of distortion of the oxygen atoms which participate in the O-H-O bridge formation at the transition state. Further, diffusion of sub-surface oxygen to fill surface oxygen vacancies of the V2O5(010) substrate has been considered and results in reactive surface sites which have not been discussed so far. NH4 diffusion at the V2O5(010) surface can be described as a combined tumbling and rotation process characterized by quite low diffusion barriers which make the adsorbate rather mobile. Finally, hydrogenation and dehydrogenation of different NH(x) species at the V2O5(010) substrate surface are studied where special emphasis is given to the influence of surface reduction simulated locally by oxygen vacancies. The results confirm experimental findings of the presence of both NH2 and NH4 species after ammonia adsorption at the V2O5(010) surface.

PMID:
23697424
DOI:
10.1063/1.4804160
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Institute of Physics
    Loading ...
    Support Center