Effect of support parameters on activity of gold catalysts: Studies of ZrO2, TiO2 and mixture

Supports based on TiO2, ZrO2 and stoichiometric mixtures such as TiZrO4 were prepared by the co-precipitation method. Samples were calcined at different temperatures to study their capacity to disperse gold nanoparticles. The method of deposition employed was direct anionic exchange (DAE). The supports alone and then the gold supported catalysts were characterized in terms of their structural, textural and surface properties, using different techniques: BET, XRD, TEM, and XPS. The oxidation of CO was chosen as the probe reaction. The results revealed that the preponderant parameters influencing the grafting of gold depend on the number of surface hydroxyls and their chemical nature.

Figure optionsDownload high-quality image (89 K)Download as PowerPoint slideResearch highlights▶ The support crystallization plays an important role in the grafting of gold. ▶ The CO oxidation reactivity of gold on amorphous TiO2 is quasi-inactive. ▶ The size of gold particles is controlled by the Au(OH)x(Cl)4−x− species. ▶ The size of gold particles is controlled by the surface support species.