Skeletal isomerization of 1-butene on tungsten oxide catalysts supported on activated carbons with various surface oxygen contents

摘要

The skeletal isomerization of 1-butene is catalyzed by solids with acid surface sites of the Bronsted type [1]. Tungsten oxide is one of the strongest acid solids among the metal oxides of the transition elements. this is due to the high oxidation state of tungsten and to the existence of double W=O bonds which allow delocalization of the ionic charge from the donation of protons, which in turn results in the stabilization of the conjugated base of the oxide [2]. In addition, Bernholc et al. [3] have shown by theoretical calculations that an additional increase in the surface acidity of the metal oxide occurs if the delocalization of the negative charge in the oxide is extended to the support. This prompted us to use carbon materials as supports for tungsten oxide catalysts because it is expected that an increase in the surface acidity of the carbon support would increase the surface acidity of the tungsten oxide-supported catalyst. The aim of this work was to investigate the influence of surface oxygen complexes on carbons on the activity of tungsten oxide supported on them in the skeletal isomerization of 1-butene.