Transfer hydrogenation of olefin from alcohol using a hydrogen-absorbing alloy (CaNi5) catalyst

Gas-phase reactions between 2-butene and 2-propanol on a hydrogen-absorbing alloy CaNi5 have been studied in the temperature range of 393 to 473 K. Ca Ni5 showed interesting characteristics as an active catalyst for the transf er hydrogenation of butene from propanol as a hydrogen donor. 2-Propanol wa s effectively dehydrogenated to yield acetone, in which the dissociated hyd rogen was completely absorbed by CaNi5 to form the metal hydride. When the alloy was hydrided to some extent, butene was effectively hydrogenated by t he absorbed hydrogen in the metal hydride to produce butane. The overall re action was expressed as catalytic transfer hydrogenation through the format ion of metal hydride intermediates (CaNi5Hn). 2-butene + 2-propanol transfer hydrogenation/CaNi5Hn butane + acetone Catalytic transfer hydrogenation on CaNi5 occurred at 423 K via hydriding o f CaNi5 by 2-propanol dehydrogenation with subsequent dehydriding for the h ydrogenation of 2-butene, rather than the direct reaction between 2-butene and 2-propanol on the alloy. (C) 1999 Elsevier Science S.A. All rights rese rved.