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چکیده
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Photo-oxidative desulfurization (PODS) properties of new MoO3-metal-organic framework composite photocatalysts were investigated by introducing the proper wt% MoO3 into a Zn(II) based MOF, [Zn(oba)(4-bpdh)0.5]n·1.5DMF (TMU-5), for the mineralization of dibenzothiophene from model oil. The addition of 3 wt % MoO3 into TMU-5 host acting as the crystal growth inhibitor was confirmed by PXRD and BET results. For the first time, under mild and green reaction conditions, 5 wt % MoO3-TMU-5 composite (MT-5) exhibited good photocatalytic activity in the model oil PODS reaction, which has no limitations in the current oxidative desulfurization catalytic systems . Only 3% of the total amount of MoO3 content in the MT catalyst is leached during the reaction. Also, the rate of PODS of MT-5 obeys the pseudo-first order equation with an apparent rate constant of 0.0305 min-1 and half-life t1/2 of 22.7 min. The radical scavengers experiments and terephthalic acid fluorescence technique confirmed that OH. and O2-.are the main reactive species in the dibenzothiophene photocatalytic degradation. The synergic effects of the active surface of TMU-5 (organic linkers as antenna) together with the active sites of MoO3, may lead to the further enhancement of the PODS activity of the MT-5 photocatalyst. Moreover, a possible photocatalytic desulfurization mechanism was proposed in the presence of MoO3-TMU-5 composites.
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