Catalytic properties of H2-reduced MoO3 and Pt/zeolites for the isomerization of pentane, hexane, and heptane

The catalytic properties of H2-reduced MoO3 for the isomerization of C5–C7 alkanes were compared to those of Pt/HY and Pt/Hβ zeolites. The pentane isomerization activity decreased in the following order: <F>Pt/Hβ>H2</F>-reduced <F>MoO3>Pt/HY</F>. In contrast, H2-reduced MoO3 exhibited the lowest activity for heptane isomerization among the catalysts tested. H2-reduced MoO3 catalyzed the isomerization of heptane more selectively than other catalysts, although no appreciable difference appeared in the selectivity for pentane isomerization. Kinetic parameters on H2-reduced MoO3 were identical with those on Pt/zeolites, suggesting that isomerization reactions on H2-reduced MoO3 proceeded via the bifunctional mechanism. We suggested from the results of 2-propanol conversion that the low dehydrogenation–hydrogenation activity of H2-reduced MoO3 was a reason for its low isomerization activity. Adsorption of heptane was found to be restricted on H2-reduced MoO3, leading to the low activity for heptane isomerization. [Copyright &y& Elsevier]