<Tr> <Td> Olefin polymerization Ziegler--Natta polymerization </Td> <Td> propylene, polypropylene </Td> <Td> TiCl on MgCl </Td> <Td> many variations exist, including some homogeneous examples </Td> </Tr> <Tr> <Td> Desulfurization of petroleum (hydrodesulfurization) </Td> <Td> H + R S (idealized organosulfur impurity), RH + H S </Td> <Td> Mo - Co on alumina </Td> <Td> produces low - sulfur hydrocarbons, sulfur recovered via the Claus process </Td> </Tr> <Ul> <Li> Reduction of nitriles for instance in a synthesis of phenethylamine with Raney nickel and ammonia: </Li> </Ul> <Li> Reduction of nitriles for instance in a synthesis of phenethylamine with Raney nickel and ammonia: </Li>

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