Synthesis of hierarchically structured alumina support with adjustable nanocrystalline aggregation towards efficient hydrodesulfurization

The development of highly active hydrodesulfurization (HDS) catalysts is still of great importance in hydroprocessing of the heavy residue oils in industry. Herein, hierarchically structured alumina hollow microspheres with high specific surface area were successfully prepared via a citric-acid-modulated hydrothermal method. With different dosages of citric acid applied, alumina microspheres were assembled with different specific surface areas, pore volumes and acidity. After the loading of the MoNi active components, a series of HDS catalysts were characterized systematically by various relevant techniques; and their catalytic activity and selectivity towards hydrodesulfurization of dibenzothiophene (DBT) were evaluated and compared. It is revealed that, the catalytic efficiency of the catalyst highly depends on the factors including the specific surface area and the acidity, the sulfidity and the dispersion of the active metal components. On this basis, we have established a facile method for preparation of hierarchically structured alumina supports with desirable physicochemical properties and high HDS catalytic efficiency. This work could also provide theoretical guidance for rational design of highly active HDS catalysts.