Three Novel Sets of Cs2H[PW4Mo8O40] Based on Various Supports: insight Into Comparative Evaluation in Oxidative Desulfurization

Abstract

Three novel heterogeneous catalysts were prepared by immobilization of a synthesized cesium salt of 4-tungsto-8-molybdophosphoric acid (abbreviated as CW4Mo8) on well prepared and modified support materials of UiO-66, microsphere SBA-15 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, N2 adsorption-desorption, SEM, and EDX methods. The Cs modification was performed to have an insoluble CW4Mo8 on the support materials. The Keggin structure of the synthesized CW4Mo8 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 DBTO2 from fuel by these catalysts. The maximum removal of 100 and 99% of DBT was achieved using CW4Mo8 supported on mesoporous SBA-15 (after 60 min) and UiO-66 (after 120 min) respectively. Furthermore, the best catalyst could be reused four times without a remarkable decrease in activity.

Keywords

• oxidative desulfurization
• heteropoly acids
• dibenzothiophene
• uio-66
• sba-15
• graphene oxide
• porous materials