Molecular structure-reactivity relationships in n-butane oxidation over bulk VPO and supported vanadia catalysts: Lessons for molecular engineering of new selective catalysts for alkane oxidation

The present study addresses the nature of the promoter effect in the bulk VPO and supported vanadia catalysts. No correlation was found between the electronegativity of the promoter or oxide support cation and the catalytic properties of these two catalytic systems. The enhancement of surface acidity had a beneficial effect on both the rate of n-butane oxidation and selectivity to maleic anhydride over the bulk VPO and supported vanadia catalysts. These findings suggested that the activation of n-butane on both the bulk and supported vanadia catalysts may require both a redox and an acid site. The results of the present study further demonstrate that the supported vanadia catalysts represent a suitable model for bulk VPO catalysts.