Three Novel Sets of Cs۲H[PW۴Mo۸O۴۰] Based on Various Supports: insight Into Comparative Evaluation in Oxidative Desulfurization

Three novel heterogeneous catalysts were prepared by immobilization of a synthesized cesium salt of ۴-tungsto-۸-molybdophosphoric acid (abbreviated as CW۴Mo۸) on well prepared and modified support materials of UiO-۶۶, microsphere SBA-۱۵ and Graphene Oxide (GO). The aim of this work was the investigation of the support effects on the Oxidative DeSulfurization (ODS) performance under a similar condition. These catalysts were characterized using FTIR, XRD, BET, BJH, N۲ adsorption-desorption, SEM, and EDX methods. The Cs modification was performed to have an insoluble CW۴Mo۸ on the support materials. The Keggin structure of the synthesized CW۴Mo۸ and well immobilization on the supports were confirmed by the characterization results. A comparative examination was performed on the capability of these nanocomposites as catalyst-adsorbent in the ODS process. Dibenzothiophene (DBT) in n-hexane was used as an oil model. The examination results indicated the special impact of the support type on the catalyst design; High surface area and porosity, and functional group type significantly affected the efficiency of DBT oxidation and adsorption of DBTO۲ from fuel by these catalysts. The maximum removal of ۱۰۰ and ۹۹% of DBT was achieved using CW۴Mo۸ supported on mesoporous SBA-۱۵ (after ۶۰ min) and UiO-۶۶ (after ۱۲۰ min) respectively. Furthermore, the best catalyst could be reused four times without a remarkable decrease in activity.

کلیدواژه ها:

Oxidative desulfurization ، Heteropoly acids ، Dibenzothiophene ، UiO-۶۶ ، SBA-۱۵ ، Graphene oxide ، Porous materials