Organic–inorganic hybrid materials [Rmim]4Mo8O26 (1-alkyl-3-methylimidazolium
polyoxomolybdate,
alkyl = n-C4H9, n-C6H13, and n-C8H17) were prepared, and various characterization techniques
have proven the hybrids’ successful synthesis. Meanwhile, the
oxidative desulfurization (ODS) performance of both model and real
diesel has been evaluated with H2O2 as the oxidant
and acetonitrile (MeCN) as the extractant. Notably, these catalysts,
initially insoluble in MeCN solution, fulfill a H2O2-responsive phase transfer into the MeCN phase to improve
the ODS performance, facilitating the S compound extraction to the
MeCN phase. After the ODS reaction, the hybrids precipitated from
the MeCN phase, completed the heterogeneous separation, and regenerated
simply by drying. Hybrid materials [Omim]4Mo8O26 (1-octyl-3-methylimidazolium polyoxomolybdate) with
the longest alkyl chain displayed the highest desulfurization efficiency,
achieving 99.8% dibenzothiophene (DBT) removal at the optimum reaction
conditions of 50 °C, O/S = 5, Mo/S = 1:1, and V(MeCN/diesel)
= 1:5. Even for real diesel, the hybrid exhibited more than 97% sulfur
removal in diesel with sulfur contents of 3000 μg/g through
the two-stage extraction-coupled oxidation desulfurization (ECODS)
process. High catalytic recycling capability has been manifested by
no obvious decrease in ODS activity after five cycles. This extraction-promoted
H2O2-responsive phase transfer catalysis guarantees
a promising industrial ODS system, not only substantially improves
the catalytic desulfurization activity but also shows superior recycling
performance with a simple catalyst regeneration method.