Synthesis of Mo-MCM-48 and their isomerization performances of n -heptane

A series of Mo-MCM-48 molecular sieves were prepared by in-situ doping method and used as the catalyst for isomerization of n-heptane. The samples were characterized by X-ray powder diffraction, scanning electron microscope, transmission electron microscope, Nitrogen adsorption desorption isotherms (N2 adsorption–desorption), NH3 temperature programmed desorption (NH3-TPD), and Fourier Transform infrared spectroscopy (FT-IR). The results showed that Mo-MCM-48 samples modified by Mo species still had the typical cubic mesoporous structure of MCM-48. The results of n-heptane isomerization showed that when the doping amount of Mo species was 0.02, the reaction temperature was 250 °C, and the reaction time was 150 min, the conversion of n-heptane and the selectivity of isoheptane of Mo-MCM-48 were up to 36.71% and 52.41%, respectively. There were no obvious decline of the catalytic activity of Mo-MCM-48 after reaction for 190 min.