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Controlling the Adsorption Enthalpy of CO 2 in Zeolites by Framework Topology and Composition
Author(s) -
Grajciar Lukáš,
Čejka Jiří,
Zukal Arnošt,
Otero Areán Carlos,
Turnes Palomino Gemma,
Nachtigall Petr
Publication year - 2012
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201200270
Subject(s) - adsorption , zeolite , enthalpy , chemistry , topology (electrical circuits) , density functional theory , molecular sieve , thermodynamics , dispersion (optics) , composition (language) , molecule , inorganic chemistry , chemical engineering , computational chemistry , organic chemistry , catalysis , physics , linguistics , mathematics , philosophy , combinatorics , optics , engineering
Zeolites are often investigated as potential adsorbents for CO 2 adsorption and separation. Depending on the zeolite topology and composition (Si/Al ratio and extra‐framework cations), the CO 2 adsorption heats at low coverages vary from −20 to −60 kJ mol −1 , and with increasing surface coverage adsorption heats either stay approximately constant or they quickly drop down. Experimental adsorption heats obtained for purely siliceous porous solids and for ion‐exchanged zeolites of the structural type MFI, FER, FAU, LTA, TUN, IMF, and ‐SVR are discussed in light of results of periodic density functional theory calculations corrected for the description of dispersion interactions. Key factors influencing the stability of CO 2 adsorption complexes are identified and discussed at the molecular level. A general model for CO 2 adsorption in zeolites and related materials is proposed and data reported in literature are evaluated with regard to the proposed model.