载Ce介孔分子筛催化剂上庚烷异构化性能研究

采用分步浸渍法制备了Ni-SiW12-Ce/Al-MCM-41双功能催化剂,通过X射线衍射(XRD)、BET和扫描电子显微镜(TEM),H2-TPR等方法对催化剂进行了表征.在常压连续流动固定床气固反应装置上,研究了催化剂的正庚烷临氢异构化反应性能,考察了催化剂制备条件对正庚烷临氢异构化反应效果的影响.结果表明,Ce的掺入改善了活性组分Ni的分散性,优化了催化剂庚烷异构化性能,同时增加了催化剂的稳定性.在Ce含量为0.8%、硅钨酸含量为20%、Ni含量4%、还原温度为400℃、还原氢气流速50 mL/min的条件下制备的催化剂的效果最好.以4%Ni-20%SiW12-0.8%Ce/Al-MCM-41为催化剂,当庚烷转化率为22.3%时,异庚烷选择性达到65.4%.

Catalytic Performance of Mesoporous Molecular Sieve in n-heptane

The Bifunctional Catalyst Ni-SiW12-Ce/Al-MCM-41 was prepared by substep impregnation method.The catalysts were characterized by using XRD,BET surface area,TEM and H2-TPR.The isomerization of n-heptane over Ni-SiW12-Ce/Al-MCM-41 catalyst was investigated in a continuous flow fixed-bed reactor under atmospheric pressure.The effect of preparation condition on the catalytic performance were studied.The result showed that the introduce of Ce is beneficial to improve catalyst performance,while increasing the stability of the catalyst Ni-SiW12-Ce/Al-MCM-41 with Ce 0.8% content,Ni 4% content and SiW12 20%content,reduction temperature 400 ℃,reduction flow rate of H2 50mL/min possessed better activity.The conversion of n-heptane and the isomerization selectivity to i-heptane could reach to 22.3% and 65.4%,respectively.