MoOx monolayers over TiO2 for the selective oxidation of isobutene

Abstract

The morphology effect of TiO2 on the dispersion of molybdena species and the performance of the resulting MoOx/TiO2 catalysts in selective oxidation of isobutene to methacrolein were examined. Two-dimensional MoOx monolayers in Mo–O–Mo bonds were well dispersed on TiO2 nanosheets that were preferentially enclosed by the {001} facets. However, aggregated MoOx clusters enriched in terminal MoO bonds were formed over TiO2 nanospindles dominated by the {101} facets. The superior performance of the MoOx monolayers, regarding activity, selectivity and stability, was ascribed to the synergetic effect between MoOx monolayers and TiO2 (001) facets.