Skeletal isomerization of
n-heptane to clean gasoline can be catalyzed by solid acids such as zeolites, sulfated zirconia, heteropoly compounds, and WO
3/ZrO
2 and their Pt or Pd-modified catalysts (bifunctional catalysts). The catalytic properties of these catalysts for isomerizations of
n-butane and
n-pentane are generally reviewed. The activation steps of alkane and factors influencing the activity and selectivity are discussed. Our study on the reaction mechanism for the isomerization of
n-butane using
13C-
n-butane is interpreted. The bimolecular mechanism is the main contributor on solid acid catalysts (sulfated zirconia and Cs
2.5H
0.5PW
12O
40). In contrast, the monomolecular mechanism is predominant over the bifunctional catalysts in the presence of H
2. The reaction pathways of
n-heptane isomerization are presented and the characteristics of this reaction are discussed. Recent reports and our data for the isomerization of
n-heptane are summarized and discussed. Pt-Cs
2.5H
0.5PW
12O
40/SiO
2 and Pd-H
4SiW
12O
40/SiO
2 are comparable to Pt-H-β in selectivity to branched heptanes and the latter heteropoly catalyst has superior activity.
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