摘要
将不同孔尺寸、酸强度的HZSM-5和Hβ分子筛混合制得复合载体,担载金属组分Ni、Mg、Mo、Zn制得烷烃异构化和芳构化催化剂M/C。采用XRD、BET、程序升温氨脱附(NH3-TPD)及吡啶吸附-脱附红外光谱法对制备的载体及催化剂进行了理化性质表征。以正辛烷为正构烷烃模型化合物,在连续加氢微型反应装置上评价了催化剂对正构烷烃异构化和芳构化反应的催化性能。结果表明,与单一分子筛相比,复合后载体的表面酸中心分布得到了调节,中强酸中心的增加有利于烷烃异构化和芳构化反应。复合分子筛催化剂引入不同金属组分进行改性后体现出不同的催化性能,其中Ni的引入既提供了加脱氢活性中心,又获得了适宜的B、L酸中心分布,使反应转化率和选择性显著提高。反应条件对催化剂的异构化和芳构化性能也有不同程度的影响,在320℃、2.8MPa、2.0h-1下,正辛烷的临氢异构化和芳构化选择性较好。
Bifunctional catalysts （M/C） were prepared by impregnating different metals （M） on composite zeolite （C） of HZSM-5 and Hβ with different acidities and pore sizes. The physicochemical characteristics of the supports and catalysts were characterized by XRD, NH3-TPD and physical adsorption. The catalytic performance of M/C in hydroisomerization and hydroaromatization was evaluated in a micro-reactor with octane as model compound. The results showed that the composite zeolite C had appropriate distribution of acidity which was beneficial to isomerization and aromatization of octane. The hydrogenation active sites could be offered and the Bronsted and Lewis acid distribution in the catalysts could be adjusted by the modification with metal like Ni, which could enhance the hydroisomerization and hydroaromatization of octane. The hydroisomerization and hydroaromatization behavior depended also on the reaction conditions and the optimized conditions were 320 ℃, 2.8 MPa and LHSV of 2.0 h^-1.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2008年第2期160-165,共6页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(20276040)
国家重点基础研究发展规划(973计划
2004CB217807)
