Abstract
The effect of various treatments such as hydrogen, hydrocarbon, carbon monoxide, and sulfur adsorption on the structure of supported platinum catalysts and the selectivities of ethyne and buta-1,3-diene hydrogenations were studied using temperature programmed reduction (TPR), radiotracer, and electron microscopy techniques. The TPR results show that hydrogen treatment at temperatures up to 773 K +4K have no effect upon the selectivity and morphology of the studied Pt-catalysts. The adsorption of these materials on the studied catalysts surfaces occurs in two stages, as primary and secondary processes. Catalytic hydrogenation is associated with the sites of the secondary process. Ethyne hydrogenation and sulphur adsorption resulted in some morphological changes to the Pt-particles of the silica-supported catalyst (Europt-1), though such changes have no influence on selectivity. The acidic sites of the alumina-support induced carbon filament formation on Europt-3 catalyst. Generally, the examined catalysts displayed similar behaviour and low selectivities towards ethyne and buta-1,3-diene are insensitive to hydrogenation and sulphur.