摘要
通过前掺杂法(PI)和浸渍法(IM)制备了氧化锰八面体分子筛(Octahedral Molecular Sieves,OMS-2)负载Pd(Pd/OMS-2)催化剂.采用X射线衍射(XRD)、H2-程序升温还原(H2-TPR)和N2-吸附/脱附等技术对样品进行了表征,研究了不同制备方法和不同Pd负载量对Pd/OMS-2催化剂催化氧化CO性能的影响,通过与载体OMS-2的比较研究了Pd/OMS-2催化剂的稳定性.结果表明,前掺杂法制备的Pd/OMS-2-PI催化剂活性明显优于浸渍法制备的Pd/OMS-2-IM催化剂,其T100分别为75℃和175℃.这与Pd/OMS-2-PI催化剂中OMS-2载体与Pd之间存在强相互作用有关.Pd负载量明显影响Pd/OMS-2-PI催化剂的催化活性,3Pd/OMS-2-PI催化剂(Pd=3.0wt%)催化活性最高,这是由于Pd掺杂进入OMS-2晶格结构,能活化晶格氧,而随Pd含量进一步增加,部分Pd分布在OMS-2表面.稳定性结果表明,Pd/OMS-2-PI稳定性明显优于OMS-2载体本身,这可能与Pd掺杂进入催化剂晶格,能较好稳定OMS-2结构密切相关.
Pd/OMS-2 catalysts were prepared by pre-ineorporation （PI） and wet impregnation （IM） methods. The influences of prepared methods and Pd loading of catalysts on the catalytic activity for CO oxidation were examined. The stability of catalysts was also investigated to compare with OMS-2. The samples were characterized by X-ray diffraction （XRD）, H2 temperaure programmed reduction （H2-TPR） and N2-adsorption/desorption. The results showed that, compared with wet impregnation method, Pd/OMS-2-PI prepared from pre-incorporation method revealed the higher catalytic activity due to the stronger interaction between Pd and OMS-2. The catalytic oxidation of CO over Pd/OMS-2-PI increased with Pd loading and reached maximum activity at 3wt% Pd. The Pd/OMS-2-PI catalyst showed significant improvement in stability with respect to the OMS-2 support. This may be due to the interaction between Pd and OMS, which maintains phase stabihy of OMS-2 support.
出处
《环境化学》
CAS
CSCD
北大核心
2013年第1期29-35,共7页
Environmental Chemistry
基金
国家自然科学基金项目(20777005)
北京市自然科学基金项目(8082008)资助
关键词
PD
OMS-2
催化氧化CO
制备方法
负载量
Pd/OMS-2, catalytic oxidation of CO, preparation methods, preparation condition.
