مرکز منطقه ای اطلاع رساني علوم و فناوري - MCF SUPPORTED V-Mo-Nb CATALYSTS PREPARED BY DIRECT HYDROTHERMAL SYNTHESIS AND IMPREGNATION METHODS FOR OXIDATIVE DEHYDROGENATION OF PROPANE

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-Mo-Nb@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 2θ 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 m²/g) were found to be higher than the surface area of the catalyst prepared by impregnation method (270 m²/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°C; O2/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.