Heteropolyacids supported on macroporous materials POM@MOF-199@LZSM-5: Highly catalytic performance in oxidative desulfurization of fuel oil with oxygen

Abstract

A highly active catalyst Keggin type POM-based inorganic-organic compound POM@MOF-199@LZSM-5(PMZ) has been prepared and applied in the catalytic oxidative desulfurization system. Structure and properties of catalyst were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and so on. The catalyst gave high desulfurization activity in the removal of DBT using O2 as the oxidant. Under the optimal conditions, the conversion rate reached 100% only in 120 min. The kinetic studies revealed that the oxidative desulfurization can present a pseudo first-order kinetic process and the apparent activation energy was 30.5 kJ/mol. The response surface method also used to optimize the process of oxidative desulfurization. There was little change for the oxidative desulfurization efficiency after 10 recycle times. This enhanced catalytic performance could be attributed to the more filled active species, POM, in the larger porous materials and the good protection measures of dual-function porous material supports.