超细Pd—B／SiO2非晶态合金加氢反应的催化活性

采用浸渍法并通过ＫＢＨ４还原制备超细Ｐｄ－Ｂ／ＳｉＯ２非晶态合金催化剂，以硝基苯加氢生成苯胺为目标反应，考察了上述催化剂的活性和选择性及热稳定性，并与晶态Ｐｄ－Ｂ／ＳｉＯ２和Ｐｄ／ＳｉＯ２催化剂及非负载型Ｐｄ－Ｂ非晶态合金催化剂进行了比较。

Study on the Preparation of Ultrafine Pd B/SiO 2 Amorphous Alloy Catalyst and Its Hydrogenation Activity

Ultrafine Pd B/SiO 2 amorphous alloy catalyst, prepared by impregnation of silica support with Pd ions and the following KBH4 reduction, was employed in the liquid phase hydrogenation of nitrobenzene to aniline. In comparison with the corresponding Pd/SiO 2 and crystalline Pd B/SiO 2 alloy catalyst, the as prepared Pd B/SiO 2 amorphous alloy catalyst exhibited better activity and selectivity to aniline, indicating the promoting effects of the amorphous structure and the alloying boron. Promoting effect of the silica support on hydrogenation activity and thermal stability of the amorphous alloy catalyst were also investigated by comparing Pd B/SiO 2 amorphous alloy catalyst with the unsupported Pd B amorphous alloy catalyst. These results and the relationship between the catalytic properties and the structural properties of Pd B/SiO 2 amorphous catalyst were discussed based on various characterizations by BET, SEM, XRD, XPS, hydrogen chemisorption, and ICP, etc.