磷铝系列分子筛催化剂的制备、表征及催化丁烷转化反应的性能

合成了AlPO 11,SAPO 11及其含杂原子Co或Mn的磷铝系列分子筛 .XRD结果证实 ,合成产物均具有AEL分子筛晶体结构 .用X射线荧光光谱测定了晶体的元素组成 ,并用NH3 TPD考察了样品的酸性和酸分布 .在以合成的分子筛为基质所制备的催化剂上进行了丁烷异构化和一步异构脱氢反应 .结果表明 ,载 0 3%Pd的SAPO 11分子筛催化剂具有最高的丁烷异构化选择性 ,而在丁烷一步异构脱氢反应中 ,含金属杂原子的催化剂具有更高的异丁烯选择性 .

Precise Control in Characteristics of Nano-particulate MFI-Type Ferrisilicate and Their Catalysis in the Conversion of Dimethyl Ether into Light Olefins

This study reports the synthesis of size-controlled Fe-MFI （Fe-substituted zeolites with the MFI topology） and their catalytic performances for DTO （dimethyl ether-to-olefins） reaction. The amount of HC1 and aging temperature were decisive factors to control the particle size of Fe-MFI in the range of 50 nm to 600 nm. The introduction of Fe3＋ ions into the zeolitic framework was confirmed by UV （ultraviolet）-visible spectroscopy. In addition, it was observed that the strength of acid site in prepared Fe-MFI was weaker than that of commercial ZSM-5. With decrease in the particle size, the amount of deposited coke decreased so that the catalyst life for the DTO reaction was well promoted. The present catalysts showed the higher light-olefin selectivity （C2= ＋ C3= ＋ C4=） than commercial ZSM-5 catalysts mainly due to the suppression of the formation of paraffins; however, the Fe-MFI catalysts were deactivated rapidly because of their low activity for the cracking of alkenes.