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

Abstract

Deep desulfurization of fuel oil is always a highly challenging issue. In this work, Zr X PTA material was obtained by directly combining the ZrIV active site with PTA, and it was found that Zr X PTA has excellent catalytic activity in the oxidative desulfurization (ODS) process. Further, Zr X PTA was loaded on γ-Al2O3 by the two-step impregnation to obtain a granular Al2O3@Zr X PTA 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@Zr X PTA maintains the high ODS activity of Zr X PTA 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@Zr X PTA is wholly derived from the counterpart of Zr X PTA, 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@Zr X PTA can be easily realized by simple filtration or decantation, and no significant activity loss was observed after five times recycling. Therefore, Al2O3@Zr X PTA has high ODS activity, high catalytic stability, and great potential as an ODS catalyst in practical applications.