The role of the extra-framework cations in the adsorption of CO2 on faujasite Y

0348361 - ÚFCH JH 2011 RIV GB eng J - Journal Article
Pirngruber, G. D. - Raybaud, P. - Belmabkhout, Y. - Čejka, Jiří - Zukal, Arnošt
The role of the extra-framework cations in the adsorption of CO2 on faujasite Y.
Physical Chemistry Chemical Physics. Roč. 12, č. 41 (2010), s. 13534-13546. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR GA203/08/0604
Institutional research plan: CEZ:AV0Z40400503
Keywords : physical chemistry * adsorption of CO2 * faujasite Y
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.454, year: 2010

A purely electrostatic picture predicts that small, more polarizing cations adsorb more strongly than the large ones. In the case of the adsorption of CO2 on faujasite Y, however, the inverse order is found at low pressure: CsY and KY adsorb stronger than NaY and LiY. This trend cannot be explained by a simple monopole–dipole or monopole–quadrupole interaction of CO2 with a single cation. Therefore, we have conducted a combined adsorption, IR and DFT study in order to shed light on this phenomenon. Our results show that a simultaneous interaction of CO2 with the cations (located in the hexagonal window between supercage and sodalite cage) and framework oxygen atoms (in the 12-ring connecting two supercages) can explain the strong adsorption of CO2 on CsY and KY. We also discuss the effect of van der Waals interactions.
Permanent Link: http://hdl.handle.net/11104/0188913