COPPER PRECURSOR EFFECT ON REDUCIBILITY AND TITANIA PHASES CONCENTRATION OF SOL-GEL Cu/TiO2 CATALYST

摘要

Cu/TiO2 catalyst was synthesized by cogelling CuSO4, or CuCl2, with titanium ethoxide. Samples were nanocrystalline with TiO2 phase concentration that depended on Cu precursor and sample annealing temperature. Phase quantitative analysis was performed by refining crystalline structure. The fresh samples prepared with CuSO4 contained almost amorphous rutile with an average crystallite size of 1.4(1) nm. Average crystallite sizes correlated well to BET areas, which were large for fresh samples and for those calcined at 400 C, and only a few square meters per gram for those calcined at 800 C. H consumption of the samples prepared with CuSO4 was 20 times larger than in those prepared with CuCl2. Reduction temperature and H consumption, which are determined by Cu-TiO2 interaction, can be explained in terms of the main defects found in nanocrystalline TiO2 phases: Ti vacancies and hydroxyls in their crystalline structure. 26 refs.