Highly dispersed Ptδ+ on TixCe(1−x)O2 as an active phase in preferential oxidation of CO

• Pt/CeO2–TiO2 is a better catalyst for PROX than Pt supported on pure oxides.
• The support is directly related with the catalyst performance.
• The absence of CeO2 hampers the O2 activation.
• The absence of TiO2 limits the activation of CO.

Structure–activity relationships for 1 wt.% Pt catalysts were investigated for a series of TixCe(1−x)O2 (x = 1, 0.98, 0.9, 0.5, 0.2 and 0) supports prepared by the sol–gel method. The catalysts prepared by impregnation were characterized in detail by applying a wide range of techniques as N2-isotherms, XRF, XRD, Raman, XPS, H2-TPR, Drifts, UV–vis, etc. and tested in the preferential oxidation of CO in the presence of H2. Also several reaction conditions were deeply analyzed. A strong correlation between catalyst performance and the electronic properties let us to propose, based in all the experimental results, a plausible reaction mechanism where several redox cycles are involved.

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