MCM-41和氧化锆负载铂-磷钨酸双功能催化剂的正戊烷临氢异构化性能

分别以MCM-41分子筛和氧化锆为载体,采用共浸渍法制备了负载Pt和磷钨酸的金属-酸性位双功能催化剂,在常压、临氢条件下研究了两种不同载体负载的催化剂对正戊烷异构化反应的催化性能;采用XRD,FTIR,XPS,NH_3-TPD等手段对试样进行了表征。表征结果显示,以氧化锆为载体的催化剂中载体与活性组分之间存在明显的相互作用,而以MCM-41分子筛为载体的催化剂中则未明显表现出载体和活性组分之间的相互作用;与以MCM-41分子筛为载体的催化剂相比,以氧化锆为载体的催化剂保持了较强的酸强度,且催化剂中的Pt元素具有更好的还原度。实验结果表明,以氧化锆为载体的催化剂在较低贵金属和磷钨酸负载量的条件下表现出更高的异构化催化性能,这可能归因于氧化锆和活性组分之间存在的相互作用、催化剂中金属组分更易被还原以及具有更高的酸强度。

Performance of MCM- 41 and ZrO2 Supported Platinum-Phosphatotungstic Acid Bifunctional Catalysts in Hysomer of n-Pentane

Pt-H_3PW_(12)O_(40)(Pt-HPA)metal-acid bifunctional catalysts supported on MCM-41 molecular sieve and ZrO_2 separately were prepared through co-impregnation method.The two catalysts were characterized by means of XRD,FTIR,XPS and NH_3-TPD,and their performances in hysomer of n-pentane were compared under atmospheric pressure.The results showed that the catalytic activity of the ZrO_2 supported catalyst,with low noble metal and phosphatotungstic acid loadings,was higher than that of the MCM-41 supported one.It was inferred that the stronger interaction between ZrO_2 and the active components,higher degree of reduction for the ZrO_2 supported samples',and the stronger acid intensity than those of the MCM-41 supported one may be the causes for the high catalytic activity.