乙醇对Pt/SAPO-11和Pt/ZSM-22催化剂烷烃异构化性能的影响

选用SAPO-11、ZSM-22两种分子筛为载体，浸渍Pt制备了Pt/SAPO-11和Pt/ZSM-22催化剂，以正庚烷为模型化合物，考察乙醇对催化剂临氢异构化反应性能的影响。并通过BET、XRD、C₂H₅OH-TPD和C₂H₅OH-FTIR等表征手段对催化剂的物化性能以及吸附反应性能和不同活性酸性位点进行了研究考察。结果表明，乙醇在临氢异构转化过程优先生成H₂O，并以H₂O的形式影响催化剂的异构化性能，催化剂异构活性与选择性随乙醇含量的增加而降低。与Pt/ZSM-22催化剂相比，Pt/SAPO-11催化剂由于有P-OH基团，表现出一定的抗含氧化物乙醇的性能。

Effect of ethanol on the isomerization of n-heptane over Pt/SAPO-11 and Pt/ZSM-22 catalysts

The hydroisomerization of n-heptane over the Pt/SAPO-11 and Pt/ZSM-22 catalysts prepared by the impregnation methods was systematically investigated in the presence of ethanol. The physicochemical properties, adsorption and reaction behaviors, and active acid sites were studied by X-ray diffraction, N₂-adsorption, C₂H₅OH-TPD and C₂H₅OH-FTIR techniques. A negative impact of alcohol was observed; the activity and selectivity to isomers decreased with the increase of the ethanol amount. Nevertheless, the effect of ethanol on the hydroisomerization over the Pt/SAPO-11 was weaker than that over the Pt/ZSM-22, showing that Pt/SAPO-11 is more resistant to oxygenated compounds due to the presence of a large amount of P-OH groups in SAPO-11. The effect of ethanol on the isomerization of n-heptane occurs through its dehydration into water over the catalysts.