Applied To The Gas-phase Hydrogenation Of Benzene Pt / R-Al <sub> 2 </ Sub> O <sub> 3 </ Sub> Surface Properties Of Research

Using temperature-programmed reduction(TPR), temperature-programmed desorption(TPD) and hydrogen-oxygen ti-trations, combined with SEM and hrdrogenation of benzene, an investigation on the surface nature and the metal-support interaction has been made for alumina-supported platinum catalysts. A series of alumina-supported platinum catalysts was prepared by ion-exchanged method with different pH value or platinum content and. treated at different temperature in oxygen or hydrogen to determine the effect of pr-eparation factors and heat treatment on the surface natureof Pt-alumina catalysts. The results show that the calca-ination are inagreement with a molecular migration mechanism. During heat treatment in hydeogen hardly any agglomeration of platinum takes place. However, a certain amountof platinum becomes "inaccessible" and cause the observed decrease in the H/Pt ratio. The results suggests the exi(?)stence of strong metal-suppoet interaction(SMSI) in the Pt-alumina system. Catalytic activity was measured in thehydrogenation of benzene to correlate the surface nature of Pt-alumina at the same time, too. It has been found that the hydrogenation activity is independent of the crystallite size of platinum and hydrogenation of benzene is a facile reaction within the range of study.