title: Synthesis Strategies for Ultrastable Zeolite GIS Polymorphs as Sorbents for Selective Separations.
abstract: Designing zeolites with tunable physicochemical properties can substantially impact their performance in commercial applications, such as adsorption, separations, catalysis, and drug delivery. Zeolite synthesis typically requires an organic structure-directing agent to produce crystals with specific pore topology. Attempts to remove organics from syntheses to achieve commercially viable methods of preparing zeolites often lead to the formation of impurities. Herein, we present organic-free syntheses of two polymorphs of the small-pore zeolite P (GIS), P1 and P2. Using a combination of adsorption measurements and density functional theory calculations, we show that GIS polymorphs are selective adsorbents for H2O relative to other light gases (e.g., H2, N2, CO2). Our findings refute prior theoretical studies postulating that GIS-type zeolites are excellent materials for CO2separation/sequestration. We also show that P2 is significantly more thermally stable than P1, which broadens the operating conditions for GIS-type zeolites in commercial applications and opens new avenues for exploring their potential use in processes such as catalysis.
authors: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA.
authors: Matthew D
authors: MD
authors: Oleksiak
authors: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA.
authors: Arian
authors: A
authors: Ghorbanpour
authors: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA.|Institute of Chemistry, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
authors: Marlon T
authors: MT
authors: Conato
authors: Applied Functional Materials, Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
authors: B Peter
authors: BP
authors: McGrail
authors: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA.
authors: Lars C
authors: LC
authors: Grabow
authors: Applied Functional Materials, Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA. radhakishan.motkuri@pnnl.gov.
authors: Radha Kishan
authors: RK
authors: Motkuri
authors: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA. jrimer@central.uh.edu.
authors: Jeffrey D
authors: JD
authors: Rimer
keywords: crystallization; density functional theory; gas/vapor adsorption; organic free; zeolite