SO2 adsorption on silica supported iridium
Artikel i vetenskaplig tidskrift, 2017

The interaction of SO2 with Ir/SiO2 was studied by simultaneous in situ diffuse reflectance infrared Fourier transform spectroscopy and mass spectrometry, exposing the sample to different SO2 concentrations ranging from 10 to 50 ppm in the temperature interval 200–400 ◦C. Evidences of adsorptionof sulfur species in both absence and presence of oxygen are found. For a pre-reduced sample in the absence of oxygen, SO2 disproportionates such that the iridium surface is rapidly saturated with adsorbed S while minor amounts of formed SO3 may adsorb on SiO2. Adding oxygen to the feed leads to the oxidation of sulfide species that either (i) desorb as SO2 and/or SO3, (ii) remain at metal sites in the form of adsorbed SO2, or (iii) spillover to the oxide support and form sulfates (SO42−). Notably, significant formation of sulfates on silica is possible only in the presence of both SO2 and O2, suggesting that SO2 oxidation to SO3 is a necessary first step in the mechanism of formation of sulfates on silica. During the formation of sulfates, a concomitant removal/rearrangement of surface silanol groups is observed. Finally, the interaction of SO2 with Ir/SiO2 depends primarily on the temperature and type of gas components but only to a minor extent on the inlet SO2 concentration.

Författare

Djamela Bounechada

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

David Philip Anderson

Kompetenscentrum katalys (KCK)

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Magnus Skoglundh

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Per-Anders Carlsson

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Journal of Chemical Physics

0021-9606 (ISSN) 1089-7690 (eISSN)

Vol. 146 084701- 084701

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Materialvetenskap

Ämneskategorier

Fysikalisk kemi

Materialkemi

DOI

10.1063/1.4976835

PubMed

28249452