Vibrational Study of SOx Adsorption on Pt/SiO2
2014 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 118, no 51, 29713-29723 p.Article in journal (Refereed) Published
The formation of ad-SOx species on Pt/SiO2 upon exposure to SO2 in concentrations ranging from 10 to 50 ppm at between 200 and 400 degrees C has been studied by in situ diffuse reflectance infrared Fourier transformed spectroscopy. In parallel, first-principles calculations have been carried out to consolidate the experimental interpretations. It was found that sulfate species form on the silica surface with a concomitant removal/rearrangement of silanol groups. Formation of ad-SOx species occurs only after SO2 oxidation to SO3 on the platinum surface. Thus, SO2 oxidation to SO3 is the first step in the SOx adsorption process, followed by spillover of SO3 to the oxide, and finally, the formation of sulfate species on the hydroxyl positions on the oxide. The sulfate formation is influenced by both temperature and SO2 concentration. Furthermore, exposure to hydrogen is shown to be sufficiently efficient as to remove ad-SOx species from the silica surface.
Place, publisher, year, edition, pages
American Chemical Society , 2014. Vol. 118, no 51, 29713-29723 p.
Physical Sciences Chemical Sciences
IdentifiersURN: urn:nbn:se:liu:diva-114017DOI: 10.1021/jp506644wISI: 000347360200028OAI: oai:DiVA.org:liu-114017DiVA: diva2:786759
Funding Agencies|Chalmers University of Technology; Swedish Energy Agency; AB Volvo; ECAPS AB; Haldor Topsoe A/S; Scania CV AB; Volvo Car Corp. AB; Wartsila Finland Oy; Swedish Research Council (VR)2015-02-062015-02-052015-03-09