Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization. The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performance. Successful encapsulation of phosphotungstic acid (HPW) and ionic liquid (BMImBr) inside the mesoporous cages of MIL-101(Cr) was accomplished through a combination of “bottle around ship” and “ship in bottle” methods. The obtained BMImPW@MIL-101(Cr) composite was characterized by XRD, FTIR, BET, SEM, XPS and ICP methods. Results indicated that the BMImPW@MIL-101(Cr) composites with PW³⁻ loading of 23.1–50.7 wt% were obtained, demonstrating that the “bottle around ship” method is beneficial to make full use of nanocages of MIL-101(Cr) to obtain expected high loading of active PW³⁻ . The BMImPW@MIL-101(Cr) exhibits excellent reusability with no evidence of leaching of active PW³⁻ and BMIm⁺, and well-preserved structure after successive cycles of regeneration and reuse. The significantly improved stability of BMImPW@MIL-101(Cr) as compared to HPW@MIL-101(Cr) is possibly because the leaching of the active PW³⁻⁻ sites can be greatly suppressed by forming large size of BMImPW owing to introduction of BMIm⁺ cation. The BMImPW@MIL-101(Cr) exhibited excellent catalytic activity for solvent free oxidative desulfurization of refractory sulfides. The enhanced oxidative desulfurization activity as compared to HPW@MIL-101(Cr) can be explained by the intimate contact of sulfides with active PW³⁻ sites owing the strong attraction of BMIm⁺ cation with the sulfides.

The non-noble metal modified sulfated zirconia was found easy to deactivate. Herein, highly active and highly stable non-noble core-shell Ni-S₂O₈²⁻/Al₂O₃@ZrO₂ catalysts (Ni-SA@Z-x, x = Al content in wt%) have been successfully prepared and investigated for n-pentane isomerization. The results showed that the core-shell Ni-SA@Z-30 provided a sustained high isopentane yield (63.1%) with little or no deactivation within 5000 min at a mild reaction pressure of 2.0 MPa, which can be attributed to the following factors: (ⅰ) carbon deposition was greatly suppressed by the large pore size and huge pore volume; (ⅱ) the loss of sulfur entities was suppressed because the small and highly dispersed tetragonal ZrO₂ particles can bond with the S species strongly; (ⅲ) strong Brønsted acidity can be maintained well after the isomerization. The pore structures and acid nature of the core-shell Ni-SA@Z-x are entirely different from those of the normal structure Ni-S₂O₈²⁻/ZrO_2-Al₂O₃, even though the Al content and the compositions of the individual components are the same. The Al₂O₃ cores endow the catalysts with high internal surface area and high mechanical strength. Meanwhile, the ZrO₂ shell, which consists of more and smaller tetragonal ZrO₂ particles because of the large surface area of the Al₂O₃ core, promotes the formation of more stable sulfur species and stronger binding sites.