Seminarium Oddziału Chemii Nanomateriałów i Katalizy
Microsoft Teams
In situ/operando analysis of gas-surface interactions by near ambient pressure XPS
dr Mykhailo Vorokhta
Department of Surface and Plasma Science, Charles University, Prague, Czech Republic
Seminarium odbędzie się zdalnie w aplikacji Microsoft Teams. Osoby posiadające konto w domenie intibs.pl mogą wziąć udział w seminarium używając kodu: 7dy1344. Pozostałe osoby proszone są o kontakt z dr inż. Piotrem Kraszkiewiczem ().
Abstract
The results of applying laboratory-based NAP-XPS for characterizations of different cerium oxide-based catalysts in realistic gaseous environments will be presented. This tool was successfully used to study both the model-thin film catalysts in-situ prepared in high vacuum and the real nanostructured layers typically tested in catalytic reactors. Using NAP-XPS, a basic understanding of the mechanisms of simple catalytic C1 reactions (water gas shift reaction, CO oxidation, methane reforming) was achieved at the molecular level. Our results on different M/CeO2 (M=Pt, Au, Co, Ni, Cu) catalyst systems demonstrated the crucial role of the nature of the metal as well as its oxidation state for the activity and system stability.
It will also be shown that NAP-XPS can be successfully used to study chemical processes on the surface of nanostructured metal-oxide based chemiresistors. (SnO2-, ZnO-, CuOx-based). The unique combination of the resistivity measurement and photoelectron study under high pressure brings a new insight into the gas sensing mechanism of studied sensors.
