Fe-doped γ-Al2O3 porous hollow microspheres for enhanced oxidative desulfurization: facile fabrication and reaction mechanism

Abstract

We report here a facile approach for the construction of 3D Fe-doped γ-Al₂O₃. In this method, by the addition of urea and citric acid during synthesis, hollow spheres with a multi-modal porous structure can be successfully produced. The obtained Fe-doped γ-Al₂O₃ microspheres are about 0.8–1.5 μm in diameter with a shell thickness of 200 nm. Compared with γ-Al₂O₃, the Fe-doped γ-Al₂O₃ catalysts exhibit enhanced activity in the selective oxidation of H₂S. According to the results of systematic studies, it is inferred that both Lewis acid sites and chemically adsorbed oxygen at oxygen vacancies have a great influence on catalytic activity. In addition, the nature of active sites and the reaction mechanism for H₂S selective oxidation over these catalysts are disclosed.