Characterisation of bimetallic platinum systems: application to the reduction of aromatics in presence of sulfur

Hydrogenation activity in presence of sulfur has been studied for bimetalli c Pt-GeAl2O3 and Pt-Pd/Al2O3 systems. It has been shown that addition of ge rmanium to platinum decreases the rate of aromatic hydrogenation whereas th e palladium-platinum system exhibits higher activity. On the basis of st pr ecise description of physico-chemical properties of bimetallic particles (c haracterisation by TEM, EXAFS, LEIS, TPR), a concept of sulfur resistant ca talyst is discussed taking into account each actor in the catalytic process and their role in the modification of the active site properties. (C) 2001 Elsevier Science B.V. All rights reserved.