Mesoporous Silica Encapsulated Phosphotungstic Acid Catalysts for Alkylation Desulfurization of Gasoline

Abstract An effective, green method was proposed to prepare mesoporous SiO 2 encapsulated phosphotungstic acid (HPW) catalysts for alkylation desulfurization of 3-methylthiophene (3-MT). 3-aminopropyl triethoxysilane (APTES) was added to promote the formation of SiO 2 gel and immobilize HPW during preparation. Then, SiO 2 encapsulated HPW catalysts were characterized by XRD, N 2 physical adsorption, SEM, TEM, EDS, Ultraviolet–Visible spectrum, FTIR, NH 3 -TPD to study the physical and chemical properties. Characterization results show that the initial Keggin structure of HPW was remained during the preparation and there exist strong interaction between HPW and SiO 2 . Activity of catalysts is superior to that of reported SBA-15 encapsulated HPW catalysts, due to more effective encapsulation of HPW. The conversion of 3-MT could reach 99% with HPW content of 30.8% under reaction conditions (reaction temperature of 363 K, reaction time of 60 min and 1% catalyst dosage). Reducing the olefin content will not reduce the conversion of 3-MT but could effectively reduce the self-polymerization of olefin, which is also beneficial to reusability of catalysts. Graphic Abstract