Heteroepitaxially grown zeolitic imidazolate framework membranes with unprecedented propylene/propane separation performances

J Am Chem Soc. 2015 Sep 30;137(38):12304-11. doi: 10.1021/jacs.5b06730. Epub 2015 Sep 18.


Propylene/propane separation is one of the most challenging separations, currently achieved by energy-intensive cryogenic distillation. Despite the great potential for energy-efficient membrane-based separations, no commercial membranes are currently available due to the limitations of current polymeric materials. Zeolitic imidazolate framework, ZIF-8, with the effective aperture size of ∼4.0 Å, has been shown to be very promising for propylene/propane separation. Despite the extensive research on ZIF-8 membranes, only a few reported ZIF-8 membranes have displayed good propylene/propane separation performances presumably due to the challenges of controlling the microstructures of polycrystalline membranes. Here we report the first well-intergrown membranes of ZIF-67 (Co-substituted ZIF-8) by heteroepitaxially growing ZIF-67 on ZIF-8 seed layers. The ZIF-67 membranes exhibited impressively high propylene/propane separation capabilities. Furthermore, when a tertiary growth of ZIF-8 layers was applied to heteroepitaxially grown ZIF-67 membranes, the membranes exhibited unprecedentedly high propylene/propane separation factors of ∼200 possibly due to enhanced grain boundary structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry
  • Alkenes / isolation & purification*
  • Imidazoles / chemical synthesis*
  • Imidazoles / chemistry
  • Particle Size
  • Propane / chemistry
  • Propane / isolation & purification*
  • Surface Properties
  • Zeolites / chemical synthesis*
  • Zeolites / chemistry


  • Alkenes
  • Imidazoles
  • Zeolites
  • propylene
  • Propane