Magnetic-heteropolyacid mesoporous catalysts for deep oxidative desulfurization of fuel: The influence on the amount of APES used.

• A novel magnetic catalysts was synthesized and characterized. • Different amount of connecting parts exposes the various number of –OCH 3 in catalysts. • Various numbers of exposed groups shows different oxidative desulfurization efficiency. • The catalyst can be easily recovered and reused by external magnet. Magnetic-heteropolyacid mesoporous catalysts have been obtained, in which magnetic Fe 3 O 4 in the center of MCM-41 mesoporous materials and APES (3-aminopropyl-triethoxysilane) used to link heteropolyacid. To noted, for the various molar ratio APES used in the synthesized process, different numbers of –OCH 3 were exposed in the final products (zero, one and two), named Fe@MP-1, Fe@MP-2 and Fe@MP-3, respectively. Interestingly, the three kinds of catalysts exhibited the various DBT removal efficiency during the oxidative desulfurization process, mainly due to their structure variance leading to be the research focus in this work. Among them, under the oxygen in air as oxidant, Fe@MP-1, with no –OCH 3 exposed outside, showed the excellent desulfurization activity with 100% DBT conversion in 90 min and behaved nearly no obvious decrease after at least 8 recycling times. Thus, the certain amount of APES, used to link active components with supporters, is suggested as an effective aspect to increase the oxidative desulfurization efficiency and maybe the different types of linkage also show the various influence, which will be focused on in our further researches. [ABSTRACT FROM AUTHOR]