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研究了以活性炭、γ- Al2 O3、γ- Al2 O3- Ti O2 为载体 ,用浸渍法制备的铂含量为 1%的担载铂催化剂 ,用于硝基苯催化加氢制对氨基苯酚 .发现 Pt/ γ- Al2 O3- Ti O2 催化剂有较高的活性、选择性和较长的寿命 ,催化剂循环使用 10次后 ,对氨基苯酚的收率仍高于 80 % ,优于常用的 Pt/ C催化剂 .测定了催化剂的比表面积、孔结构以及活性金属铂的分散度 ,发现孔结构与催化剂性能之间没有规律性的关系 ;而铂在 γ- Al2 O3- Ti O2 上的分散度最高 ,对氨基苯酚的收率也最高 .用 TPR、TPD、XPS对催化剂表征的结果表明 ,Pt- Ti O2 之间的强相互作用是改变 Pt/ γ-Al2 O3- Ti O2 催化剂性能的主要原因之一
The supported platinum catalyst prepared by impregnation method with activated carbon, γ-Al 2 O 3 and γ-Al 2 O 3 -Ti O2 as support was used to catalyze the hydrogenation of nitrobenzene to p-aminophenol. The Pt / γ-Al 2 O 3 -TiO 2 catalyst has higher activity, selectivity and longer lifetime. After the catalyst is recycled for 10 times, the yield of p-aminophenol is still above 80%, which is better than the conventional Pt / C The specific surface area, pore structure and dispersion degree of active metal platinum were measured. It was found that there was no regular relationship between the pore structure and the catalyst performance. However, the dispersion of platinum on γ-Al 2 O 3 -TiO 2 was the highest. The yield of aminophenol was the highest.The results of characterization of catalysts by TPR, TPD and XPS showed that the strong interaction between Pt-Ti O2 was one of the main reasons to change the performance of Pt / γ-Al 2 O 3 -TiO 2 catalyst