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Identification of Intermediates in the Reaction Pathway of SO$_{2}$ on the CaO Surface: From Physisorption to Sulfite to Sulfate

Schewe, Nils ORCID iD icon 1; Maleki, Farahnaz; Di Liberto, Giovanni; Gerdes, Andreas 1; Idriss, Hicham 1; Idriss, H. 1; Pacchioni, Gianfranco
1 Institut für Funktionelle Grenzflächen (IFG), Karlsruher Institut für Technologie (KIT)

Abstract:

The interaction of CaO and Ca(OH)$_{2}$ with solvated or gaseous SO$_{2}$ plays a crucial role in the corrosion of urban infrastructure by acid rain or in the removal of SO$_{2}$ from flue gas. We carried out a combined spectroscopic and theoretical investigation on the interaction of SO$_{2}$ with a CaO(001) single crystal. First, the surface chemistry of SO$_{2}$ was investigated at different temperatures using polarization-resolved IR reflection absorption spectroscopy. Three species were identified, and an in-depth density functional theory study was carried out, which allowed deriving a consistent picture. Unexpectedly, low temperature exposure to SO$_{2}$ solely yields a physisorbed species. Only above 100 K, the transformation of this weakly bound adsorbate first to a chemisorbed sulfite and then to a sulfate occurs, effectively passivatating the surface. Our results provide the basis for more efficient strategies in corrosion protection of urban infrastructure and in lime-based desulfurization of flue gas.


Verlagsausgabe §
DOI: 10.5445/IR/1000157407
Veröffentlicht am 17.04.2023
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Funktionelle Grenzflächen (IFG)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2023
Sprache Englisch
Identifikator ISSN: 0947-6539, 1521-3765
KITopen-ID: 1000157407
HGF-Programm 43.33.11 (POF IV, LK 01) Adaptive and Bioinstructive Materials Systems
Erschienen in Chemistry – A European Journal
Verlag John Wiley and Sons
Band 29
Heft 23
Seiten e202203956
Vorab online veröffentlicht am 16.03.2023
Nachgewiesen in Dimensions
Web of Science
Scopus
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