Hiding extra-framework cations in zeolites L and Y by internal ion exchange and its effect on CO₂ adsorption

Abstract

La-exchange of zeolites by combined aqueous and solid-state cation exchange enables control of their CO2 adsorption isotherm shape.

Structural Chemistry, Flexibility, and CO2 Adsorption Performance of Alkali Metal Forms of Merlinoite with a Framework Si/Al Ratio of 4.2

“…These values are consistent with other heats of adsorption of CO 2 measured for K-forms of the zeolites Y (34−39 kJ mol −1 ) 38 and L (35 kJ mol −1 ). 39 As the K 6.2 -MER material shows rapid kinetics, reasonable CO 2 /CH 4 selectivity, and furthermore was available in >20 g batches, we investigated it for application by embedding the powder within alumina beads, as described in the Methods. No crystallization of alumina hydrate was observed upon heating the mixture at 573 K for 12 h, as shown by XRD in Figure S10.1.…”

“…An independent estimate of 35 ± 1 kJ mol –1 for the Henry law region was made via the ZLC data, also described in Section S9. These values are consistent with other heats of adsorption of CO 2 measured for K-forms of the zeolites Y (34–39 kJ mol –1 ) and L (35 kJ mol –1 ) …”

High Selectivity and Adsorption Capacity of Cation-Exchanged Zeolites for Biogas, Syngas, and Flue Gas Separation in a Pressure Swing Adsorption Unit

“…The majority of the studies were conducted with experimental and molecular simulations, which allows the evaluation and comparison of our findings and predictions to strengthen the reliability and accuracy of our results . Nonetheless, the well-defined motivation for selecting zeolites for this study was the feasibility of tuning their affinity toward CO 2 and delivering high selectivity and adsorption capacity in binary-component mixtures (CO 2 :H 2 ; CO 2 :CH 4 ; CO 2 :N 2 ). − The reported and widely employed strategy to tune their affinity for CO 2 consists of introducing cations in the zeolite framework cavity …”

Magnetic orientation behavior of L-type zeolite with rare-earth elements under low magnetic field

“…Table S3 † shows that K + in K-L is mainly distributed at three sites: K1 (site B), K2 (site E) and K3 (site D), which is consistent with previous reports. 20,22,23 Table S4 † indicates that the decrease in K + occurs mainly in K1 (site B) and that the exchange of Ho 3+ occurs mainly in K1 (site B). This was also the case for Gd-L and Er-L (Tables S5 and S6 †).…”