Synthesis of ZSM-22 with Enhanced Acidity Using Alcoholamine as a Structure-Directing Agent to Promote the Hydroisomerization of n-Heptane

The physiochemical properties and catalytic performanceof zeoliterely on the judicious selection of organic structure-directing agents(OSDAs), among which alcoholamines are rarely used. Here, we reportthat 6-amino-1-hexanol (AH) can be used as an OSDA for the generationof commercially viable ZSM-22 with a Si/Al ratio window of 35-150.Compared with ZSM-22 derived from commonly used 1,6-diaminohexane(DAH), the samples generated using AH possess improved crystallinityand more intermediate-to-strong acid site, which can be attributedto the stronger host-guest interactions between AH and zeoliteframework. In addition, the crystallization process can be acceleratedby the use of AH. ZSM-22 catalysts derived from AH outperform thecounterpart generated from DAH in hydroisomerization of n-heptane, and improved catalytic activity and isomer yield can beachieved thanks to the presence of abundant acid sites and high crystallinity.