Carneiro J.T., Yang C.-C., Moma J.A., Moulijn J.A., Mul G.
Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL Delft, Netherlands; Project Au-TEK Catalysis, Advanced Materials Division, MINTEK, Private Bag X3015, Randburg, South Africa
Carneiro, J.T., Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL Delft, Netherlands; Yang, C.-C., Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL Delft, Netherlands; Moma, J.A., Project Au-TEK Catalysis, Advanced Materials Division, MINTEK, Private Bag X3015, Randburg, South Africa; Moulijn, J.A., Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL Delft, Netherlands; Mul, G., Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL Delft, Netherlands
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. © 2009 The Author(s).