Abstract

Highly dispersed alumina-supported iridium and iridium-rhenium catalysts were prepared to study the effect of the metal loading and the addition of Re on the surface properties and on the resistance to sulfur poisoning of Ir/Al 2O 3 catalysts using an organometallic precursor, Ir(acac) 2. Particle size in the Ir catalysts was modified using different metal loading ranging from 0.5 to 3.0 Ir wt.%. A bimetallic Ir-Re catalyst, containing 1 wt.%Ir and 0.5 wt% Re was also studied. The catalysts were characterized by H 2 chemisorption, temperature programmed reduction, temperature programmed desorption of ammonia and XPS. The catalysts were used in toluene hydrogenation and the thiotolerance level was measured with a feed containing 10 ppm of thiophene. It was found that the sulfur tolerance increases as metal particle size increases and with the addition of Re.