Catalysis Letters · 2009 · 65 citations · 31 references
Natural SciencesChemistryMaterials ScienceCatalysisSurface ChemistrySurface ScienceCatalyst CharacterizationCatalytic MaterialsCatalytic MechanismsPhotocatalysisPhotochemistrySupported CatalystsCatalytic ActivityGold DepositionPhotocatalytic MaterialsPhotocatalytic OxidationPhotocatalytic Surface ReactionsSelective OxidationSurface CompositionSurface Functional Groups
Gold deposition on Hombikat UV100 was found to negatively affect the activity of this Anatase catalyst in selective photo-oxidation of cyclohexane. By ammonia TPD and DRIFT spectroscopy it was determined that the Au deposition procedure leads to a significant decrease in OH-group density (mol m−2 BET) on Hombikat, suggesting that the amount of surface OH-groups, rather than the presence or absence of Au, is determining the catalytic performance. The importance of surface OH-groups was demonstrated by comparing the performance of Hombikat (with and without Au deposition) to surface propoxylated TiO2, synthesized by a sol–gel method from titanium (IV) isopropoxide. The effect of the deposition recipe of noble metals on the surface composition of TiO2 should thus be taken into account in evaluating and explaining photocatalytic performance of TiO2 modified by noble metals (Au), in particular in non-aqueous phase reactions.
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Size- and support-dependency in the catalysis of gold
Masatake Haruta · Catalysis Today · 1997 · 4.1K citations