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