Preparation Of La₂O₃-V₂O₅/MCM-41 Catalyst And Performance For Ethylbenzene Dehydrogenation

A series of La₂O₃-V₂O₅/MCM-41 catalysts with high specific surface area were prepared by means of incipient wetness impregnation for the dehydrogenation of ethylbenzene to styrene using CO₂ as oxidant. At 600oC, conversion of ethylbenzene over 10La15V/MCM-41 after an on-stream time of 4 h was ca. 86.5% and was still above 70% after reaction of 8 h. The selectivity to styrene remained above 91.0% after 4 h. The high catalytic activity and stability of 10La15V/MCM-41 during dehydrogenation of ethylbenzene is attributed to an ideal La/V atomic ratio. The formation of amorphous carbon species on the outer surface of La₂O₃-V₂O₅/MCM-41 would result in catalyst deactivation. We introduced La₂O₃ into V-based/MCM-41 catalyst as the promoter and obtained a satisfactory result. MCM-41 is more frequently used in the field of catalysis as a novel support due to its unique properties. We reported the catalytic behavior of La₂O₃-V₂O₅/MCM-41 sample in the EBDH in the presence of CO₂ in order to enhance the conversion of ethylbenzene and the selectivity of styrene.The catalyst properties were characterized by means of X-ray diffraction (XRD), BET surface area, Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectra (XPS) and high-resolution transmit electron microscopy (HRTEM) techniques, respectively.