Mono- and heterometallic carbonyl precursor based RuMo/Al2O3 catalysts: hydrodesulfurization activity and temperature programmed studies

The effects of preparation process and starting material on hydrodesulfuriz ation (HDS) activity of alumina supported ruthenium, molybdenum and rutheni um-molybdenum hydrotreating catalysts were investigated. Conventional impre gnation method and gradual gas phase adsorption were compared as a preparat ion route. The HDS tests showed that controlled gas phase deposition is adv antageous in the preparation of the monometallic catalyst systems. The most promising HDS activity was achieved with the RuMo/Al2O3 catalyst prepared from binuclear organometallic complex. This suggests that the direct ruthen ium-molybdenum bond in the structure of the catalyst precursor favors the f ormation of highly active surface phase. The oxidation and reduction behavi or of the catalysts was studied by oxygen pulse chemisorption (PCO) and tem perature programmed reduction (TPR), A clear relationship was observed betw een the method of preparation and the reactivity of the surface species. (C ) 2001 Elsevier Science B.V. All rights reserved.