AlMCM-41负载Ni催化剂的正十二烷加氢转化反应性能研究

采用N_2脱附、XRD，NH_3-TPD和H_2-TPR等手段表征中孔分子筛AlMCM-41负载 Ni催化剂。结果表明，AlMCM-41负载Ni后会导致中孔分子筛骨架部分塌陷，孔道有 序度降低，而且，Ni与载体的相互作用随着载体中铝含量的增加而增强。此外，催 化剂的表面酸性以弱酸和中强酸为主。正十二烷加氢转化反应评价表明，在催化剂 Si/Al比为17.4 ～ 38.7范围内，随着铝含量的减少，氢解副反应加剧，正十烷的 转化率逐渐升高，异构选择率则以先增加后减小的趋势变化，在Si/Al=23.2时达到 最大值。当Si/Al比为17.4时，催化剂的酸/金属功能呈现较好的匹配，正十二烷裂 解产物以C_6为中心呈对称分布且i/n-(C_4～C_9)比例较高。

Performance of Nickel Supported AlMCM-41 Catalyst in the Hydroconversion of n-Dodecane

A series of Ni catalysts supporled on AIMCM-41 with different Si/Al ratio were prepared and characterized by N2 absorption, XRD, NH3-TPD and H2-TPR. It was shown that a part of AIMCM-41 framework collapsed and the interaction of Ni oxidic species with support increased with the increase of Al content after nickel impregnation. In addition, the acidity of the catalysts was mostly weak-medium one. The evaluation of the catalysts in the /i-dodecane hydroconversion showed that, when the Si/Al ratio increased in the range of 17.4 ~ 38.7, the apparent n- dodecane conversion and the hydrogenolysis selectivity increased, while the isomerization selectivity passed through a maximum at Si/Al = 23.2 and then decreased. At Si/Al = 17.4, the metal/acid function of the catalyst was nearly in balance. The carbon number distribution of cracked products was symmetrical about C6 and the higher t/n-(C4 ~ Cg) ratio could be obtained.