| Noble metal hydrogen spillover effect has been applied on the Co-Clay hydrotreating catalysts to increase their catalytic activity as well as to increase their lifetime. Direct impregnation technique was used for the loading of noble metals on the clay support while an ion-exchange method was followed for cobalt loading. Temperature programmed reduction (TPR) measurement technique has been applied to measure the hydrogen spillover effects of the supported catalysts. The reduction temperatures of the promoted catalysts have been found to decrease, indicating that the hydrogen spillover has taken place on the catalyst surface. Pulse microreactor activity results for hydrodesulfurization (HDS) of thiophene and cumene cracking are presented, results show that a small amount of noble metal/metals can increase the catalytic activity of the catalysts. Two promising catalysts have been evaluated in a batch autoclave reactor for the performance test using vacuum gas oil (VGO) as a feed, these catalysts have been found to have a higher and sustained activity compared to the unpromoted Co-Clay catalyst. The elemental analysis of the spent catalysts shows that the amount of coke deposition on the noble metal promoted catalysts are significantly less than the unpromoted catalyst. Thus this research reveals the fact that hydrogen spillover can create, maintain and regenerate the catalytic activity of Co-Clay catalysts for an extended period of time. |
