模板剂和助剂对Pt/MOR催化剂临氢异构催化性能的影响

在分别以十二烷基苯磺酸钠（SDBS）、复合聚乙二醇20000（PEG20000）和十六烷基三甲基溴化铵（CTAB）为模板剂合成的梯级孔MOR分子筛上负载Pt制备了Pt/MOR催化剂，并用分步浸渍法在所得催化剂上分别引入第二金属组分Ni和Cr；采用XRD、N2吸附-脱附、CO脉冲化学吸附、H2-TPR、NH3-TPD和Py-IR等技术对所得样品进行了表征。结果表明：复合模板剂的添加有效地引入了介孔，所得MOR的介孔表面积和介孔体积分别从36.4%和52.9%增加到54.2%和76.5%，平均孔径从2.1 nm增加到3.9 nm；Ni或Cr的引入明显增加了催化剂的总酸量和L酸量，显著改善了金属Pt的分散度，且Cr的作用效果优于Ni。在引入1% Cr的Pt/MOR催化剂上，正辛烷临氢异构的转化率可达59.3%，其异构产物选择性可达94.9%。

EFFECTS OF TEMPLATE AND ADDITIVES ON HYDROISOMERIZATION PERFORMANCE OF Pt/MOR CATALYST

Hierarchical pore MOR zeolites were synthesized by using sodium dodecyl benzene sulfonate(SDBS), composite polyethylene glycol 20000(PEG20000) and cetyltrimethylammonium bromide(CTAB) as templates, respectively. Pt/MOR catalysts were prepared by loading Pt on MOR zeolites and the second metal components Ni and Cr were respectively introduced into the obtained catalyst by sequential impregnation method. The samples were characterized by XRD, BET, CO pulse chemical adsorption, H2-TPR, NH3-TPD and Py-IR. The results showed that the mesoporous are effectively introduced by the addition of composite templates, the mesoporous surface area and volume of the MOR prepared increase from 36.4% and 52.9% to 54.2% and 76.5%, respectively, and its average pore diameter increases from 2.1 nm to 3.9nm. The introduction of Ni or Cr significantly increases the total acidity and Lewis acid of the catalyst, and remarkably improves the dispersity of the Pt species, and the effect of Cr is better than that of Ni. Over the Pt/MOR catalyst with 1% Cr, the n-octane conversion reaches to 59.3% with the isomerization selectivity of 94.9%.