Gold catalysts adsorption characteristics

The objectives of this work are to study the influence of gold particles on the properties of typical catalyst supports, namely MgO and TiO. Gold has been chosen because of its relatively low catalytic activity except for oxygen transfer reactions (4). MgO, an insulator, and TiO, a semiconducting material, are widely used as catalyst supports, and for both of them metal-support interactions have been reported in the literature. Our study places main emphasis on the role of gold on thermal stability, phase transformations, solid-phase oxygen exchange activity, and adsorption characteristics of the oxides. 

Isotherm I is typical of adsorption in micropores, which occurs, for instance, in zeolites and in activated carbons. Isotherm II represents multilayer physisorption on a flat surface (valid for many nonporous substances). Type HI and V isotherms are characteristics of weak gas-solid interactions (water adsorption on gold and bromine adsorption on silica are good examples). The type IV isotherm is frequently found in the study of heterogeneous catalysts its shape is characteristics... 

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