Preparation and High Performance of La2O3-V2O5/MCM-41 Catalysts for Ethylbenzene Dehydrogenation in the Presence of CO2

摘要

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°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.