Photocatalytic Isomerization of Butenes over ZnO and SnO2

Article abstract of DOI:10.1246/bcsj.58.2307

It has been found with ZnO as well as TiO2 that 2-butene is much more reactive than 1-butene for their photocatalytic isomerization.Although both cis-trans and double bond isomerizations take place on ZnO, only cis-trans isomerizations occurs over SnO2.The photocatalytic isomerization were suppressed drastically in the presence of NO.From those results together with the ESR studies the following conclusions emerge; a butene molecule interacts with the photoformed O^- to form a radical species as a result of fission of the C=C bond; the photocatalytic isomerization proceeds via such a radical intermediate; the lack of the reactivity of 1-butene appears to be explicable on such basis.