Novel High-Activity Al2O3@ZrXPTA Catalysts and Their Catalytic Oxidative Desulfurization, Mechanism, and Molding

Deep desulfurization of fuel oil is always a highly challenging issue. In this work, ZrXPTA material was obtained by directly combining the ZrIV active site with PTA, and it was found that ZrXPTA has excellent catalytic activity in the oxidative desulfurization (ODS) process. Further, ZrXPTA was loaded on γ-Al2O3 by the two-step impregnation to obtain a granular Al2O3@ZrXPTA composite. The successful synthesis of the material was verified by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and N2 adsorption–desorption. The results show that Al2O3@ZrXPTA maintains the high ODS activity of ZrXPTA and realizes the rapid and complete removal of dibenzothiophene under mild reaction conditions (T = 40 °C, O/S = 4, t = 30 min). The mechanism study shows that the ODS activity of Al2O3@ZrXPTA is wholly derived from the counterpart of ZrXPTA, which benefits from the synergistic catalytic effect between the ZrIV active site and PTA. The direct binding of these two active sites makes the synergistic effect fully exerted. In addition, the recovery of Al2O3@ZrXPTA can be easily realized by simple filtration or decantation, and no significant activity loss was observed after five times recycling. Therefore, Al2O3@ZrXPTA has high ODS activity, high catalytic stability, and great potential as an ODS catalyst in practical applications.