Control of the size of platinum particles on silica surfaces using organic-inorganic composites

A series of two tartaric acid-silica (sol-gel and impreg tart-SiO(2)) composites with different tartaric acid contents were prepared using sol-gel and impregnation methods, and then a series of two platinum-silica composites (impregsol-gel Pt-SiO(2) and impreg;impreg Pt-SiO(2)) were obtained by impregnating sol-gel and impreg tart-SiO(2) with a platinum Solution, followed by drying and calcining. The platinum-silica composites which were obtained were characterized by XRD, N(2) and H(2) adsorption and SEM. From the results, it is concluded that the distribution and particle size of platinum in Pt-SiO(2) can be controlled by using two types of tartaric acid-silica composites with different tartaric acid contents, while keeping the platinum loading constant.