ZSM-23 in n-Alkane Hydroisomerization
Sourc:The SiteAddtime:2026/4/3 Click:0
ZSM-23 is widely used as a catalyst support in n-alkane hydroisomerization, a key process in refining for improving the cold-flow properties of diesel and lubricating oils. Its one-dimensional 10-membered ring pore structure (MTT topology) provides shape selectivity that favors branching of linear alkanes over cracking, especially when combined with noble metals like Pt or Pd to form bifunctional catalysts.
Key features that make ZSM-23 effective in this application include:
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Controlled acidity: High Si/Al ratios yield strong but well-spaced Brønsted acid sites, minimizing unwanted cracking.
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Pore-mouth catalysis: Due to its non-intersecting channels, reactions often occur near pore entrances, promoting selective formation of mono-branched isomers.
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Resistance to coking: The narrow, straight channels reduce deep coke formation compared to larger-pore zeolites.
Studies have shown that Pt/ZSM-23 catalysts exhibit high selectivity toward mono-methyl branched isomers of long-chain n-alkanes (e.g., n-hexadecane), which significantly lower pour points while preserving high cetane numbers—making it ideal for dewaxing
