C-6 HYDROCARBON CONVERSIONS OVER SILICA-SUPPORTED AND ALUMINA-SUPPORTED PALLADIUM CATALYSTS

The reactions of conversion of three Cg hydrocarbons: n-hexane, 2,2-di methylbutane and methylcyclopentane in excess hydrogen appeared very i nteresting probes in assessing the state of palladium in silica- and a lumina-supported catalysts. Pronounced variations in catalytic activit y and selectivity for isomerization and aromatization are suggestive o f significant modifications of the catalysts caused by high temperatur e pretreatment (Pd silicide formation in tile case of Pd/SiO2 or incre ase of acidity for Pd/gamma-Al2O3).