MCF SUPPORTED V-Mo-Nb CATALYSTS PREPARED BY DIRECT HYDROTHERMAL SYNTHESIS AND IMPREGNATION METHODS FOR OXIDATIVE DEHYDROGENATION OF PROPANE


YAŞYERLİ S., Aktas O.

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, vol.27, no.1, pp.49-58, 2012 (SCI-Expanded) identifier identifier

Abstract

Vanadium (V), molybdenum (Mo) and niobium (Nb) incorporated MCF ("Mesocellular Silica Foams") supported catalysts were prepared by direct hydrothermal (V-Mo-Nb-MCF) and impregnation (V-MoNb@MCF) methods for oxidative dehydrogenation of propane (ODHP) to produce propylene. Also, different amounts of V (V/Si mole ratios: 0.031, 0.062, 0.124) incorporated MCF supported V-MCF catalysts were synthesized by direct hydrothermal method and tested for ODHP reaction. The XRD patterns of V-MCF and V-Mo-Nb-MCF catalysts showed that there was no peak corresponding to V, Mo and Nb metals at high 2 theta region. MoO3 peak was observed in the XRD pattern of V-Mo-Nb@MCF catalyst prepared by the impregnation method. BET surface areas of the catalysts synthesized by hydrothermal method (664-996 m(2)/g) were found to be higher than the surface area of the catalyst prepared by impregnation method (270 m(2)/g). Using Mo and Nb metals together with V in the V-Mo-Nb@MCF catalyst prepared by impregnation increased propane conversion (up to 12%) and decreased propylene selectivity on ODHP catalytic test studies (550 degrees C; O-2/C3H8/He:3/6/21) in the fixed bed reactor system. The propane conversion value of V-Mo-Nb-MCF catalysts synthesized by hydrothermal route was low while the propylene selectivity (81%) of this catalyst was found to be significantly high.