Chemistry Department Seminar

Despite the great efforts devoted to the development of alternative energy sources, fossil fuels will probably continue to dominate the scene, particularly for transportation purposes. The refining industry relies mainly on conventional solid catalysts and heterogeneous reactions for the manufacture of gasoline and diesel; however, current and future environmental regulations impose stringent specifications on the quality and the chemical composition of such fuels, which cannot be routinely achieved by current technologies. Therefore, novel catalytic approaches are needed in order to produce gasoline and diesel with the required purity.
Transition metal complexes and homogeneous catalytic processes have become common tools in the chemical industry, particularly in fine chemicals and pharmaceuticals, but their potential in relation to fuel manufacture has been largely neglected. In this talk we will describe some attempts to make use of organometallic chemistry and homogeneous or liquid biphasic catalysis to understand or to promote some reactions related to fuel upgrading issues:
. • The first example discusses the structures, bonding and reactions of Rh, Ir, and Ru complexes of thiophenes, benzothiophenes and dibenzothiophenes; this chemistry is analyzed in the context of modeling key species and reactions implicated in the industrially important hydrodesulfurization (HDS) process, while drawing mechanistic parallels between organometallic and surface chemistry. Also, the development of some water-soluble catalysts for the aqueous biphasic hydrogenation of benzothiophene, as a possible pretreatment to enhance HDS of refinery cuts, will be described.
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. • The second topic deals with the design of new homogeneous and aqueous or ionic liquid biphasic alkene hydroformylation catalysts derived from Rh and Ru phosphine complexes, as a possible means of upgrading gasoline by the in situ carbonylation of undesirable olefins in naphtha to produce environmentally ac