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This work constitutes a new trial to enhance the properties of palladium supported on alumina modified with zirconium used as catalysts for methane combustion. The effect of the support drying mode is studied. For this aim, Al2O3-ZrO2 binary oxides with zirconium loading of 2 and 5% in weight were prepared using sol–gel process then dried under ordinary or supercritical conditions. Palladium with a loading of 0.5% was deposited on the support by wet impregnation. Several techniques have been used to investigate differences between the two types of the derived catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Various PdO–support interactions could be obtained on the Pd/SiO2–Al2O3 catalyst prepared by the method adopted in this work. Higher palladium dispersion, lower palladium reduction temperature and better catalytic activity in methane combustion are obtained on the Pd/SiO2–Al2O3 catalyst when PdO–Si interaction is favoured than PdO–Al interaction. In addition, compared to the Pd/SiO2 and the Pd/Al2O3 catalysts, higher catalytic activity is obtained on the Pd/SiO2–Al2O3 solids due to their moderate acidity strength. [Copyright &y& Elsevier]

Abstract: This work constitutes an attempt to control the properties of palladium supported on alumina doped with zirconium used in methane oxidation. For this aim, two zirconium precursors were used and sol–gel method was adopted to prepare such catalysts. N2 physisorption, XRD, scanning electron microscopy, H2 chemisorption, H2 TPR and NH3 TPD are the main techniques used to characterize the catalysts. The use of different zirconium precursor affects significantly the textural and the structural properties of these materials. Furthermore, the catalytic activity is seen to depend on the zirconium precursor and the zirconium content simultaneously. [ABSTRACT FROM AUTHOR]