Preparation and high performance of La2O3-V2O5/MCM-41 catalysts for ethylbenzene dehydrogenation in the presence of CO2

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 600 degrees C, the conversion of ethylbenzene and selectivity to styrene over 10La15V/MCM-41 after an on-stream time of 4 h was about 86.5 and 91.0%, respectively. The properties of the catalysts before and after the reaction were characterized using techniques such as X-ray diffraction, specific surface area, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, and oxidation. The high catalytic activity and stability of 10La15V/MCM-41 during dehydrogenation of ethylbenzene is attributed to an optimized La/V atomic ratio. The accumulation of amorphous carbon species on the external surface of La2O3-V2O5/MCM-41 is the cause for catalyst deactivation.