Henry constants predicted using multipole expansion for the interaction energies

Abstract

ABSTRACT:In line with the former studies of our group concerning the ab initio (parameter-free) calculation of adsorption-related properties, a new simple and powerful method is presented and applied to the adsorption of N 2 , O 2 , CO, CO 2 , and C 2 H 2 in zeolite Y. The calculation method is investigated and some refinements on the calculation strategy are introduced. The calculation method is based on the expansion of the interaction energy in terms of the multipole moments and polarizabilities. The molecular electrical properties were calculated at a high level on the B3LYP/cc-aug-pV(Q or 5)Z. A relationship between the van der Waals radius and the radius of an atom of the interacting molecule in a charge field is proposed.

Adsorption of the Butene Isomers in Faujasite: A Combined ab-Initio Theoretical and Experimental Study

“…In the past, our group has already studied very intensively the adsorption properties of small molecules in zeolite-type adsorbents on an ab-initio level. [8][9][10][11][12][13] Full ab-initio, non-empirical calculation strategies were presented for the prediction of Henry constants, heats of adsorption, separation constants, and adsorption energy surfaces. 13 On the other hand, other groups presented the first quantum chemically calculated isotherm.…”

“…The ab initio study of adsorption properties is still computationally demanding, but with the ever increasing computing power these “theoretical experiments” will become more accessible. In the past, our group has already studied very intensively the adsorption properties of small molecules in zeolite-type adsorbents on an ab-initio level. − Full ab-initio, non-empirical calculation strategies were presented for the prediction of Henry constants, heats of adsorption, separation constants, and adsorption energy surfaces . On the other hand, other groups presented the first quantum chemically calculated isotherm …”

Ammonium adsorption on Brønsted acidic centers on low-index vanadium pentoxide surfaces

“…Moreover, such a model would allow estimation of the adsorption site strength based solely on the geometry of the final structure of the V 2 O 5 -OH–NH 3 complex without the need to calculate the geometry and energy of the V 2 O 5 –OH reference model (thus shortening the calculation procedure). The usefulness of the electrostatic potential for predicting adsorption phenomena (such as interaction energies) has already been demonstrated by Tielens and Geerlings [99]. …”

Exploring the reactivity of intraframework vanadium, niobium and tantalum sites in zeolitic materials using the molecular electrostatic potential

“…As a natural prolongation of our previous works on the reactivity of zeolites [21][22][23][24][25][26] we analyze in this paper the reactivity of zeolitic materials with group 5 elements using a hard descriptor, namely the Molecular Electrostatic Potential (MEP), within a periodic DFT approach. We will show that the differences in reactivity between the group 5 elements can be used to tune the zeolite's catalytic activity.…”