摘要
在DM-Ⅱ高硅沸石担载的Fe-MnO催化剂中添加碱性助剂可提高催化剂的活性及C_2~=～C_4~=烯烃选择性,且随着碱性增强,催化剂性能不断改善,随助剂MnO含量的增加,低碳烯烃的选择性不断提高,而催化剂活性有一极大值。研究表明,金属活性组分以适当的粒度分散在分子筛表面,MnO可提高其分散度,添加碱性助剂不利于金属组分的还原,但其“电子效应”却显著改善了催化剂性能,MnO能促进铁的还原,从而提高了催化剂的活性。
The catalytic activity and C2-C4 selectivity of DM-Ⅱ zeolite supported Fe-MnO catalyst are both enhanced obviously by adding basic promoter, the effectiveness is in sequence of K>Na>Li. By adding MnO promoter, C2=-C4= selectivity increases with increasing MnO content. It is shown that metal active component is highly dispersed on the surface of DM-Ⅱ zeolite when MnO is added. The reduction of Fe becomes difficult due to the action of alkali, the enhancement of the catalytic activity is attributed to the electronic effect of alkali. Because MnO promotes the reduction of Fe, the catalytic activity is increased.
基金
国家自然科学基金
