用户名: 密码: 验证码:
负载型Fe、Ni催化剂的气相沉积法制备及其催化性能
详细信息    查看官网全文
摘要
负载型Fe、Ni基催化剂在轻烷烃的催化转化过程有重要的应用[1]。本课题组长期致力于研究新型负载型VIII族金属催化剂制备方法、催化应用以及构效关系。以Fe(cp)2为前驱体,使用气相沉积法进行Al_2O_3负载型Fe催化剂制备(VD-Fe/Al_2O_3),结合两步法焙烧过程,我们发现所制备的VD-Fe/Al_2O_3随着载气流速或者温度变化其Fe含量都出现了最大值。机理研究表明,近90%Fe(cp)2分子在沉积之初以物理吸附形式存在于载体表面,而大约10%的分子发生了化学反应从而固定在载体表面。该机理决定了必须通过仔细控制的焙烧过程,才能使Fe组分尽可能留在载体表面。我们将该催化剂用于催化过氧化氢分解、乙烷氧化等反应,发现VD-Fe/Al_2O_3表现出比浸渍法制备的相同Fe含量催化剂具有明显更好的活性。对于Ni基催化剂也在多种载体上成功实现气相沉积法的制备,其催化性能与浸渍法相比也体现了一定的优越性。
Supported Fe and Ni catalysts are widely applied in the catalytic conversion of light alkanes.Fe(cp)2 was used as the precursor to prepared Al_2O_3 supported Fe catalyst with vapor deposition(VD-Fe/Al_2O_3),which involves a combined two-step calcination.The iron loading of the catalyst have a maximum value with the varying deposition temperature and flow rate of carrier gas.The result of mechanistic study shows that around 90% of Fe(cp)2 molecules exist on the support surface by physical adsorption,and around 10% anchors on the support surface via chemical reaction.This catalyst was used for catalytic reactions such as oxidation of ethane,decomposition of hydrogen peroxide,etc.The VD-Fe/Al_2O_3 catalyst exhibits higher catalytic activity compared to the catalysts with the same Fe loading that prepared by impregnation.Ni based catalysts were also being successfully prepared through vapor deposition.and they also showed superior catalytic performance over the catalysts prepared by impregnation.
引文
[1]Lin,X;Poeppelmeier,K.R.;Weitz,E.Appl.Catal.A 2010,381:114.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700