改性Pd/C、Ru/C贵金属催化剂在丙二烯磷酸选择加氢中的应用

【作者】 赵立红；

【导师】 苏运来；

【作者基本信息】 郑州大学 ， 工业催化， 2006， 硕士

【摘要】 磷霉素是一种新型的广谱抗菌药，在我国的医药行业中占有重要地位。工业上以化学合成法进行生产，其中由丙二烯磷酸选择加氢生成丙烯磷酸是关键一步，多以Pd／C作为加氢催化剂。 本论文对不同来源的三种活性炭进行预处理，并以其为载体制备了Ru／C催化剂；制备了Ru、Fe、Co、Ni改性的Pd／C催化剂，以期改善催化剂的性能；制备了Ru负载量不同的Ru／C催化剂和部分s区、d区和f区组分改性的Ru／C催化剂。制备的催化剂通过两个反应来评价其性能，一是用于磷霉素合成中的丙二烯磷酸选择加氢生成丙烯磷酸反应；二是用于丙酮常压加氢反应重，通过反应初活性来评价催化剂活化氢能力，该反应可以作为一个将催化剂用于其它加氢反应的参考。 所制备的催化剂经过H₂-TPR表征，考察了活性组分的还原行为；H₂-TPD实验表征了催化剂表面吸附氢中心及数量，进行了XRD、XPS和BET比表面孔结构测定，以期得到催化剂表面结构和性能之间的关系。 硝酸处理使活性炭表面含氧基团数量增加，增加了溢流氢的数量，提高了催化剂用于丙二烯磷酸选择加氢反应的转化率。 Ru组分改性Pd／C催化剂，当Pd／Ru=3／1时，Pd晶粒适中，α活性中心数量多，催化剂用于丙二烯磷酸反应转化率最高，。 Fe、Co组分改性Pd／C催化剂α活性中心数量减少，增加了一个中等强度的β活性中心，Pd基催化剂的H₂-TPD结果表明：α活性中心主要由Pd和Ru两者共同作用，β活性中心主要是Ru金属；α活性中心数量越多，用于丙二烯磷酸选择加氢反应转化率越高，活性组分分散度越高，用于丙酮常压加氢反应的初活性越高。 改性Ru／C催化剂研究表明，s区和f区组分改性Ru／C催化剂用于丙二烯磷酸选择加氢反应转化率大部分高于Ru／C催化剂；d区组分改性Ru／C催化剂的转化率均低于Ru／C催化剂。Ba组分改性显著提高了Ru／C催化剂的α活性中心数量，用于丙二烯磷酸选择加氢反应转化率显著高于Ru／C催化剂。更多还原

【Abstract】 Phosphonomycin is a new broad antibacterial whose antimicrobial spectrum is much broad. In the industry manufacture, phosphonomycin is obtained through chemical synthesis. One step is preparing from 1, 2-proprnyl-phosphonic acid with palladium supported on activated carbon to cis-1-propenyl acid.Thermal or chemical pretreatments were prepared before the Ru metal impregnation to introduce oxygen groups. Pd/C catalysts promoted by Ru, Fe, Co, Ni catalysts were prepared to improve the catalytic activity. Ru/C catalysts with different loading amount were prepared. Ru/C catalysts promoted by several metal components were prepared. The catalytic activity of the catalysts were appraised by the selective hydrogenation of 1,2-proprnyl-phosphonic acid to cis-1-propenyl acid and the acetone hydrogenation respectively.The catalysts have been characterized by H₂-TPR, H₂-TPD, XRD, XPS and BET in order to obtain the relation between the surface characterization and the catalytic activity.The H2-TPR and H2-TPD results showed that the surface oxygen groups and the spillover hydrogen increased after nitric acid treatment. This facilitated the conversion from 1,2-proprnyl-phosphonic acid to cis-1-propenyl acid.When Pd/Ru=3/1, Pd-Ru/C catalyst had the maximal hydrogenation activity. The results showed that the Pd crystal is moderate and there is a big amount of hydrogen in a adsorption center.Pd/C catalysts promoted by Fe, Co had two low-temperature peaks （first peak:α active center, second peak :β active center） .The hydrogen adsorbed on the a active center decreased. The results showed that the first peak was assigned to the hydrogen adsorbed on the Ru and Pd. The second peak was attributed to the hydrogen adsorbed on the Ru metal. As the hydrogen adsorbed on a active center increased, the conversion from 1, 2-proprnyl-phosphonic acid to cis-1-propenyl acid increased, so did the the acetone hydrogenation.The results showed that Ru/C promoted by components in s section and f section improved the conversion of the selective hydrogenation reaction, while Ru/C promoted by the components in d section had the lower conversion. Ru/C promoted by Ba markedly improved the hydrogen adsorbed on a active center and the更多还原