Rare Earth Metals Ion-exchanged β-Zeolites as Supports of Platinum Catalysts for Hydroisomerization of n-Heptane

• Published in: Chinese journal of chemical engineering Vol. 19; no. 2; pp. 278 - 284
• Main Author: 刘平 姚月 张兴光 王军
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2011
• Subjects: bifunctional catalyst; Catalysis; Catalysts; Conversion; hydroisomerization of n-heptane; Inductively coupled plasma; Optimization; Platinum; Rare earth metals; Selectivity; β-zeolite; 临氢异构化; 分子筛; 正庚烷; 电感耦合等离子体; 稀土; 程序升温还原; 金属离子交换; 铂催化剂; β-zeolite; Ce; hydroisomerization of n-heptane; bifunctional catalyst; La
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(11)60166-3

A series of Pt catalysts supported on the Hβ-zeolite that is ion-exchanged with the rare earth metal ions of Ce（III） and La（III）,are prepared by impregnation,characterized by inductively coupled plasma （ICP）,X-ray diffraction （XRD）,BET,temperature-programmed desorption of ammonia （NH3-TPD）,temperature-programmed reduction of hydrogen （H2-TPR） and H2-chemisorption techniques,and evaluated in the hydroisomerization of n-heptane with an atmospheric fixed-bed reactor.The reaction temperature,time on stream,space velocity,and the ratio of H2/n-heptane are changed to get the optimal conditions.The Ce（III） and La（III）-exchanged Hβ-zeolites exhibit higher selectivity for isomerized products than the neat Hβ-zeolite.Moreover,the Ce（III）-exchanged catalysts give higher conversions of n-heptane,whereas the La（III）-exchanged ones do not show any improvement in con-version.Under optimal conditions,the catalyst with 0.4% （by mass） Pt and 0.5% （by mass） Ce loading presents very high selectivity of isomerized products of 95.1% coupled with high n-heptane conversion of 68.7%.Effects of the ion-exchange of Ce（III） and La（III） on the catalytic performance are discussed in relation with the physico-chemical properties of catalysts.