A comparative in situ XPS study of PtRuCo catalyst in methanol steam reforming and water gas shift reactions

• Published in: Catalysis today 2010-11, Vol.157 (1), p.250-256
• Main Authors: Zafeiratos, S., Paloukis, F., Papakonstantinou, G., Teschner, D., Hävecker, M., Vass, E., Schnörch, P., Knop-Gericke, A., Schlögl, R., Moreno, B., Chinarro, E., Jurado, J.R., Neophytides, S.G.
• Format: Article
• Language: English
• Subjects: Ambient pressure photoelectron spectroscopy; Applied sciences; Catalysis; Chemistry; Direct methanol fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; General and physical chemistry; Methanol steam reforming reaction; PtRuCo catalyst; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Water gas shift reaction
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2010.03.030

In the present study the oxidation state and the surface composition of a ternary PtRuCo catalyst were investigated under methanol steam reforming (SRM) and water gas shift (WGS) reaction conditions at 570 K. Ambient pressure X-ray photoelectron spectroscopy (APPES) was applied in situ at 0.5 mbar, while simultaneously monitoring the catalytic activity of the sample by on-line mass spectrometry. Non-destructive depth profile measurements performed under SRM reaction conditions over a polycrystalline PtCo foil, were also used to obtain detailed depth-resolved information. The results showed that surface segregation of cobalt and modification of its oxidation state occurs when switching from SRM to WGS reaction conditions. Evidence of ionic Pt was found only during WGS reaction, while Ru was mainly present in the metallic state. The results clearly demonstrate the dynamic response of the PtRuCo catalytic surface to the reaction atmosphere.