Research on Properties of Sn and Si Doped AlPO4-5 Molecular Sieve and Its Hydrodesulfurization Reaction

, Abstract ： The S A P O - 5 and S n S A P O - 5 molecular sieves were successfully prepared by directly adding Si and Sn'+ sources into the gel. The physical and chemical jiroperties of molecular sieves were investigated by XRI), low tem­ perature N : physical adsorption, S E M , N M R , Py-IR and With the increase of Sn content, the cr\rstal surface of S n S A P O - 5 is smoother and the appearance is more regular hexagonal prisms. The Sn and Si are more con-cenlrated on the surface of molecular sieves. In addition, the framework Al is replaced by Sn 2+, causing defects in the framework, im!)alance of cliarges and more acidic sites. The molecular sieves were used to modify tlie N i W cata­ lyst, and dihenzotliiophene ( D B T ) in the simulated oil was used as a prol)e to evaluate the H D S performance of their modified hydrogenation catalysts. The addition of S n S A P O - 5 in the catalyst introduces more acidic* sites, im­ proves the interaction between support and active metals, promotes the suliidation of active metals, and forms more metal active phases, thereby the hydrodesulfurization capacity of the N i W catalyst was improved. Therefore, the catalyst modified by S n S A P O - 5 has better H D S activity than other catalysts, and has better application prospect.