超细Pd-B/SiO_2非晶态合金加氢反应的催化活性  

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

作　　者：余锡宾[1] 王明辉[1] 叶林美 刘波[1] 李和兴[1] 邓景发[2] 

机构地区：[1]上海师范大学化学系 [2]复旦大学化学系

出　　处：《分子催化》1999年第1期3-8,共6页Journal of Molecular Catalysis(China)

摘　　要：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（ＮＢ）加氢生成苯胺（ＡＮ）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．研究表明，Ｐｄ－Ｂ／ＳｉＯ２非晶态合金在ＮＢ加氢反应的催化活性和选择性方面显著优于晶态Ｐｄ－Ｂ／ＳｉＯ２和Ｐｄ／ＳｉＯ２催化剂，表明所形成的非晶态结构以及类金属Ｂ的修饰有利于ＮＢ的催化加氢；另一方面，Ｐｄ－Ｂ／ＳｉＯ２非晶态合金的催化活性和选择性及热稳定性均优于Ｐｄ－Ｂ非晶态合金，表明引入载体有利于改善Ｐｄ－Ｂ非晶态合金的催化性能．结合ＢＥＴ、ＩＣＰ、ＸＲＤ、ＸＰＳ、氢吸附等表征技术，讨论了超细Ｐｄ－Ｂ／ＳｉＯ２非晶态合金的催化性能与催化剂结构的关系．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.

关 键 词：非晶态合金 硝基苯 加氢 钯 硼 苯胺 催化剂 

分 类 号：O643.36[理学—物理化学] O625.631[理学—化学]