First-Principles Study on the Mechanism of Photoselective Catalytic Reduction of NO by NH3 on Anatase TiO2(101) Surface
2014 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 118, no 12, 6359-6364 p.Article in journal (Refereed) Published
A promising method for NO abatement is photoselective reduction with a proper semiconductor, such as TiO2. Here we report a systematic theoretical study on NO abatement through an adsorbed NH3 molecule on the anatase TiO2(101) surface. The reaction mechanism proposed by experiments has been verified. The key process, namely, the oxidation of the adsorbed NH3 molecule by photogenerated hole, has been investigated by two different methods: one is to use the triplet state to mimic the real excited state and the other is to inject a hole to the slab by the adsorption of center dot OH radical. Both methods give almost the same result, and the oxidation of the NH3 molecule is found to be a concerted proton coupled charge transfer process. The center dot NH2 radical, resulting from the oxidation of NH3, can be attacked by a NO molecule from the gas phase to form a NH2NO complex spontaneously. The decomposition of this complex to N-2 and H2O is the rate limiting step of the overall reaction. This multistep decomposition process consists of the following sequences: the H atom transfers to the O atom in the molecule first to form HNNOH that further decomposes to N-2 and OH groups, and the latter group recombines to produce the H2O molecule.
Place, publisher, year, edition, pages
2014. Vol. 118, no 12, 6359-6364 p.
Free radical reactions, Free radicals, Molecules, Oxidation, Surface reactions, Titanium dioxide, Catalytic reduction, Charge transfer process, Decomposition process, First-principles study, Photogenerated holes, Rate-limiting steps, Reaction mechanism, Theoretical study
IdentifiersURN: urn:nbn:se:kth:diva-144942DOI: 10.1021/jp501427kISI: 000333578300043ScopusID: 2-s2.0-84897389524OAI: oai:DiVA.org:kth-144942DiVA: diva2:715500
QC 201405052014-05-052014-05-052014-05-22Bibliographically approved