Hierarchical nanofabrication of microporous crystals with ordered mesoporosity

• Published in: Nature materials Vol. 7; no. 12; pp. 984 - 991
• Main Authors: Fan, Wei, Snyder, Mark A., Kumar, Sandeep, Lee, Pyung-Soo, Yoo, Won Cheol, McCormick, Alon V., Lee Penn, R., Stein, Andreas, Tsapatsis, Michael
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.12.2008; Nature Publishing Group
• Subjects: Biomaterials; Carbon; Chemical engineering; Chemical synthesis; Chemistry and Materials Science; Condensed Matter Physics; Crystal growth; Crystallization; Crystals; Materials Science; Nanocrystals; Nanotechnology; Optical and Electronic Materials; Silica; Zeolites
• ISSN: 1476-1122; 1476-4660; 1476-4660
• DOI: 10.1038/nmat2302

Shaped zeolite nanocrystals and larger zeolite particles with three-dimensionally ordered mesoporous (3DOm) features hold exciting technological implications for manufacturing thin, oriented molecular sieve films and realizing new selective, molecularly accessible and robust catalysts. A recognized means for controlled synthesis of such nanoparticulate and imprinted materials revolves around templating approaches, yet identification of an appropriately versatile template has remained elusive. Because of their highly interconnected pore space, ordered mesoporous carbon replicas serve as conceptually attractive materials for carrying out confined synthesis of zeolite crystals. Here, we demonstrate how a wide range of crystal morphologies can be realized through such confined growth within 3DOm carbon, synthesized by replication of colloidal crystals composed of size-tunable (about 10–40 nm) silica nanoparticles. Confined crystal growth within these templates leads to size-tunable, uniformly shaped silicalite-1 nanocrystals as well as 3DOm-imprinted single-crystal zeolite particles. In addition, novel crystal morphologies, consisting of faceted crystal outgrowths from primary crystalline particles have been discovered, providing new insight into constricted crystal growth mechanisms underlying confined synthesis. Zeolite nanocrystals with three-dimensionally ordered mesoporous structures are important for designing molecularly accessible and selective catalysts. With a single zeolite synthesis procedure, uniform nanocrystals and crystal zeolites with ordered imprinted mesoporosity can now be obtained.