Synthesis of Discrete CHA Zeolite Nanocrystals without Organic Templates for Selective CO₂ Capture

Abstract

Small‐pore zeolites such as chabazite (CHA) are excellent candidates for the selective separation of CO2; 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 CO2 molecules in the host structure was revealed by 3D electron diffraction (3D ED). The high sorption capacity for CO2 (3.8 mmol g−1 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 CO2 storage capacity (8 CO2 per unit cell) and high selectivity (no CH4 was adsorbed).

Synthesis of Discrete CHA Zeolite Nanocrystals without Organic Templates for Selective CO2 Capture

“…The measurements were performed following a procedure presented in Figure . [34] Bonds between Si/Al (tetrahedral sites) and oxygens, D6R and 8MR units, and sites for extra-framework cations (…”

Sulfated zirconium oxide-decorated magnetite KCC-1 as a durable and recyclable adsorbent for the efficient removal of asphaltene from crude oil

“…The results obtained in this regard are in accordance with the results presented by the researchers. 28,30,45 This study shows that at different temperatures, increasing the asphaltene concentration increases the adsorption on the adsorbent. Thus, aer 2 h, the adsorbent is saturated and reaches its equilibrium adsorption capacity (Fig.…”

Discrimination of Aluminum from Silicon by Electron Crystallography with the JUNGFRAU Detector

“…Furthermore, we processed our data with XDS. Other data reduction programs, like PETS, can be more easily combined with dynamical refinement, e.g., with JANA2006, which can reveal finer structural details than a pure kinematic approach [45][46][47][48].…”