Synthesis of Discrete CHA Zeolite Nanocrystals without Organic Templates for Selective CO 2 Capture

• Published in: Angewandte Chemie International Edition Vol. 59; no. 52; pp. 23491 - 23495
• Main Authors: Debost, Maxime, Klar, Paul B, Barrier, Nicolas, Clatworthy, Edwin B, Grand, Julien, Laine, Fabien, Brázda, Petr, Palatinus, Lukas, Nesterenko, Nikolai, Boullay, Philippe, Mintova, Svetlana
• Format: Journal Article
• Language: English
• Published: Germany Wiley-VCH Verlag 21-12-2020
• Subjects: Chemical Sciences; in situ PXRD; nanozeolites; CO2 adsorption; precession-assisted 3D ED; template-free synthesis; Nanozeolites; Precession-assisted 3D ED; Template-free synthesis; In situ PXRD
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202009397

Small-pore zeolites such as chabazite (CHA) are excellent candidates for the selective separation of CO
; however, the current synthesis involves several steps and the use of organic structure-directing agent (OSDA), increasing their cost and energy requirements. We report the synthesis of small-pore zeolite crystals (aluminosilicate) with CHA-type framework structure by direct synthesis in a colloidal suspension containing a mixture of inorganic cations only (Na
, K
, and Cs
). The location of CO
molecules in the host structure was revealed by 3D electron diffraction (3D ED). The high sorption capacity for CO
(3.8 mmol g
at 121 kPa), structural stability and regenerability of the discreate CHA zeolite nanocrystals is maintained for 10 consecutive cycles without any visible degradation. The CHA zeolite (Si:Al=2) reaches an almost perfect CO
storage capacity (8 CO
per unit cell) and high selectivity (no CH
was adsorbed).