Characterization of the metallic phase in nanocrystalline ZnAl2O4-supported Pt catalysts

In this study several complementary methods as XRD, HRTEM, O2 and H2 adsorption, as well as H2–O2 titration were used for characterization of the metallic phase in 0.5–3.0 wt.% Pt/ZnAl2O4 catalysts. Three nanocrystalline ZnAl2O4 spinels used as a supports were prepared by the solvothermal and co-precipitation method. It was found that irrespective of the preparation method they form very good support materials with a high capacity to achieve high platinum dispersion. O2 and H2 chemisorption data showed metal dispersion up to 90% and good correspondence with HRTEM results was observed. The H2–O2 titration method may be applied for determination of Pt dispersion only in the high-loaded Pt/ZnAl2O4 catalysts. The catalytic performances of Pt supported on the prepared spinels were evaluated in the propane total oxidation reaction.