镁铝复合氧化物载体的制备与性质研究

以硝酸镁和硝酸铝为原料，用氨水溶液作为pH调节剂，采用共沉淀法制备了镁铝复合氧化物载体，研究了制备过程中镁铝比、pH调节剂种类、水解过程pH值的大小、反应温度、焙烧温度及回流晶化温度对复合氧化物载体理化性质的影响。并以RFCC汽油加氢脱硫为探针反应，考察了以镁铝复合氧化物为载体的催化剂选择性加氢脱硫性能。实验结果表明，在镁铝分子比为10、反应温度为80℃、pH值为9.5条件下制备的镁铝复合氧化物载体具有适宜的比表面积和均匀的孔分布，且晶型较完整，结晶度高。以该复合氧化物为载体制备的催化剂具有良好的RFCC汽油选择性加氢脱硫反应性能。

Preparation and property of magnesium-aluminum composite oxides

The supports of magnesium aluminum composite oxides were prepared by co precipitation method using magnesium nitrate and aluminum nitrate as starting materials with ammonia solution as pH agent. The effects of magnesium aluminum ratio, the kind of pH agent, pH value in the hydrolytic process, reaction temperature, calcination temperature, and crystallization temperature on the physicochemical characteristics of the magnesium aluminum composite oxides were studied systematically in this paper. The selective hydrodesulphurization (SHDS) properties of the catalyst supported on the magnesium aluminum composite oxides were investigated with the SHDS of residual fluid catalytic cracking (RFCC) gasoline as probe reaction. The results showed that the support of magnesium aluminum composite oxides which was prepared at the ratio of magnesium to aluminum (Mg/Al) being 10, reaction temperature of 80℃ and the pH of 9.5, had proper specific surface area, uniform pore distribution and integrated crystal structure with high degree of crystallization. The catalyst supported on this kind of composite oxides performed well for SHDS of the RFCC gasoline.