In Situ Ambient Pressure XPS Study of CO Oxidation Reaction on Pd(111) Surfaces
2012; American Chemical Society; Volume: 116; Issue: 35 Linguagem: Inglês
10.1021/jp301636u
ISSN1932-7455
AutoresRyo Toyoshima, Masaaki Yoshida, Yuji Monya, Yuka Kousa, Kazuma Suzuki, Hitoshi Abe, Bongjin Simon Mun, Kazuhiko Mase, Kenta Amemiya, Hiroshi Kondoh,
Tópico(s)Catalysis and Oxidation Reactions
ResumoThe CO oxidation reaction on the Pd(111) model catalyst at various temperatures (200–400 °C) under hundreds mTorr pressure conditions has been monitored by in situ ambient pressure X-ray photoelectron spectroscopy and mass spectroscopy. In situ observation of the reaction revealed that the Pd(111) surface is covered by CO molecules at a lower temperature (200 °C), while at higher temperatures (300–400 °C) several oxide phases are formed on the surface. We found that the reactivity is enhanced in the presence of a surface oxide and significantly suppressed by formation of a cluster oxide and the PdO bulk oxide. CO titration experiments suggest that less coordinated oxygen atoms are more reactive for CO oxidation.
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