Dual-templating of macroporous multicomponent MoVTeNbO x catalysts for propane ammoxidation to acrylonitrile

Abstract

Thermally stable ordered porous MoVTeNbO x phases displaying both macroporous and mesoporous structures were prepared for the first time by a dual-templating approach employing colloidal arrays of polystyrene spheres and non-ionic surfactants. The MoVTeNbO x phases possessing such dual porosity were obtained after polystyrene spheres and non-ionic surfactants were removed in a low temperature calcination step. These hierarchical MoVTeNbO x phases displaying bimodal pore structure transformed into macroporous rutile phase possessing nanocrystalline inorganic walls at high temperature. These MoVTeNbO x rutile phases possessed high surface areas (70 m2/g), desirable pore architectures, robust nanocrystalline inorganic walls, and enhanced thermal stability (up to 600 °C). Although these macroporous MoVTeNbO x rutile catalysts displayed lower activity in propane ammoxidation and lower acrylonitrile selectivity in propane ammoxidation as compared to the active and selective M1 phase, the novel synthesis method reported in these studies represents a promising general approach to design novel complex mixed metal oxides for a wide range of applications in selective oxidation catalysis.