Rhodium hydrodesulfurization

Supported Rhodium Catalysts Alkali Promoters on Metal Surfaces Cobalt-Molybdenum Sulfide Hydrodesulfurization Catalysts Chromium Oxide Polymerization Catalysts... 

Removal of thiophene impurities from petroleum feedstocks is accomplished by a process called hydrodesulfurization (HDS) which involves the insertion of metals into the thiophene ring between the C-S bond. In order to better understand the mechanism of this reaction, different groups have utilized selenophene model systems due to the enhanced NMR characteristics of Se. Metal complexes of selenophenes that have been studied include rhodium <19970M2751>, molybdenum <2006POL499>, manganese <20010M3617, 19950M332>, chromium... 

While metal complexes capable of desulfurizing or hydrodesulfurizing thiophenes are relatively numerous, homogeneous catalysts are very rare, being limited to rhodium and iridium TRIPHOS precursors that are unique in tolerating the harsh experimental conditions required for the second C-S bond cleavage of thiophenes [2 b]. 

Tungsten alloyed with nickel, cobalt, or rhodium in thin layers on alumina supports, also sulfided, is used on an industrial scale as a catalyst in crude oil processing (hydrotreating, hydrocracking, reforming, hydrodesulfurization, and hydrodenitrogenation), as well as in Fischer-Tropsch synthesis (alcohol formation from CO + H2). 

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