Synthesis and adsorption investigations of zeolites MCM-22 and MCM-49 modified by alkali metal cations

Abstract

Ion exchange was made on MCM-22 and MCM-49 zeolites with different Si/Al molar ratios, with Li + , Na + , K + , and Cs + ions and the study of the influence of alkali metal cations on CO 2 adsorption properties was performed. The degree of ion-exchange decreased for larger cations (Cs + ) apparently due to steric hindrances. The exchange with different cations led to a decrease in the surface area and the micropore volume. Our study shows that the adsorption capacity of the tested zeolites depends significantly on the nature and the concentration of the charge-compensating cations. The highest CO 2 adsorption capacity was obtained on the MWW zeolites with the lowest Si/Al molar ratio and the Li + or K + cations.Keywords MCM-22 zeolite · MCM-49 zeolite · Alkali metal cation exchange · N 2 and CO 2 adsorption Abbreviations S BET BET surface area, m 2 /g S external external surface area, m 2 /g V total total pore volume, cm 3 /g V micro micropore volume, cm 3 /g K H Henry's constant, cm 3 /g STP

Isosteric heats of adsorption of carbon dioxide on zeolite MCM-22 modified by alkali metal cations

“…1) Textural properties of the MCM-22 zeolites used for CO 2 adsorption were determined from the nitrogen adsorption data published in the foregoing paper (Pawlesa et al 2007). The main texture parameters, i.e.…”

“…Although extensive experimental and theoretical works on the adsorption of CO 2 on different zeolites were published, to our knowledge there is only one report concerning the isothermal study of CO 2 adsorption on MCM-22 zeolite (Pawlesa et al 2007). This zeolite (IZA code MWW) crystallizes as thin sheets or plates and has unique and unusual structure (Rubin and Chu 1990;Lawton et al 1998).…”

“…In our previous paper we report on the influence of alkali metal cations on the carbon dioxide adsorption properties at 273 K using ion-exchanged MCM-22 zeolites (Pawlesa et al 2007). We evidenced the decisive influence of the nature and the concentration of the charge-compensating cations on the CO 2 adsorption capacity of MCM-22 zeolite.…”

Adsorbent Materials for Carbon Dioxide Capture from Large Anthropogenic Point Sources

“…Similar to this work, Zukal showed that the CO 2 adsorption capacities of MCM-49 (MWW) derivatives varied with changes in the cation type and the aluminum amount, with the Na-exchanged MCM-49 with the highest aluminum content exhibiting the maximum CO 2 adsorption. [35] The CO 2 adsorption properties of zeolites are also influenced by the porous characteristics of the framework. From a comparative study of the CO 2 adsorption capacities on a number of commercially available zeolites including 4A, 5A (both LTA), 13X, APG-II, and WE-G 592 (all FAU), Siriwardane reported that the highest adsorption capacities were observed in zeolite 13X, the material with the largest pore diameter and volume among those studied.…”

Layered Materials with Catalytic Applications: Pillared and Delaminated Zeolites from MWW Precursors

“…On the contrary, aminegrafting on zeolites resulted in an increase in CO 2 /N 2 selectivity, and more elevated heats of CO 2 adsorption implied a strong reduction in CO 2 capture capacity. Specifically, NH 2 -ITQ-2 showed exceptionally high CO 2 /N 2 selectivity combined with the best separation capacity among the studied MWW-type zeolites [157][158][159][160][161].…”