Direct Observation and Modelling of Ordered Hydrogen Adsorption and Catalyzed ortho-para Conversion on ETS-10 Titanosilicate Material | Sciact - CRIS-system of Boreskov Institute of Catalysis

Direct Observation and Modelling of Ordered Hydrogen Adsorption and Catalyzed ortho-para Conversion on ETS-10 Titanosilicate Material Full article

Journal

PCCP: Physical Chemistry Chemical Physics
ISSN: 1463-9076 , E-ISSN: 1463-9084

Output data

Year: 2007, Volume: 9, Number: 21, Pages: 2753-2760 Pages count : 8 DOI: 10.1039/b703409a

Tags

MICROPOROUS TITANOSILICATE; VIBRATIONAL SPECTROSCOPY; MOLECULAR-HYDROGEN; STORAGE MATERIALS; HIGH RESOLUTION; H-2; Na; CO; FRAMEWORKS; ZEOLITES

Authors

Ricchiardi Gabriele ¹ , Vitillo Jenny G. ¹ , Cocina Donato ² , Gribov Evgueni N. ³ , Zecchina Adriano ¹

Affiliations

1	Dipartimento di Chimica IFM and NIS Centre of Excellence, Università di Torino, INSTM UdR Università, Via Pietro Giuria 7, Torino, Italy
2	Dipartimento di Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino, Italy
3	Boreskov Institute of Catalysis, pr. akad. Lavrentieva 5, Novosibirsk, Russia

Hydrogen physisorption on porous high surface materials is investigated for the purpose of hydrogen storage and hydrogen separation, because of its simplicity and intrinsic reversibility. For these purposes, the understanding of the binding of dihydrogen to materials, of the structure of the adsorbed phase and of the ortho–para conversion during thermal and pressure cycles are crucial for the development of new hydrogen adsorbents. We report the direct observation by IR spectroscopic methods of structured hydrogen adsorption on a porous titanosilicate (ETS-10), with resolution of the kinetics of the ortho–para transition, and an interpretation of the structure of the adsorbed phase based on classical atomistic simulations. Distinct infrared signals of o- and p-H2 in different adsorbed states are measured, and the conversion of o- to p-H2 is monitored over a timescale of hours, indicating the presence of a catalyzed reaction. Hydrogen adsorption occurs in three different regimes characterized by well separated IR manifestations: at low pressures ordered 1 : 1 adducts with Na and K ions exposed in the channels of the material are formed, which gradually convert into ordered 2 : 1 adducts. Further addition of H2 occurs only through the formation of a disordered condensed phase. The binding enthalpy of the Na+−H2 1 : 1 adduct is of −8.7 ± 0.1 kJ mol−1, as measured spectroscopically. Modeling of the weak interaction of H2 with the materials requires an accurate force field with a precise description of both dispersion and electrostatics. A novel three body force field for molecular hydrogen is presented, based on the fitting of an accurate PES for the H2–H2 interaction to the experimental dipole polarizability and quadrupole moment. Molecular mechanics simulations of hydrogen adsorption at different coverages confirm the three regimes of adsorption and the structure of the adsorbed phase.

Ricchiardi G. , Vitillo J.G. , Cocina D. , Gribov E.N. , Zecchina A.
Direct Observation and Modelling of Ordered Hydrogen Adsorption and Catalyzed ortho-para Conversion on ETS-10 Titanosilicate Material
PCCP: Physical Chemistry Chemical Physics. 2007. V.9. N21. P.2753-2760. DOI: 10.1039/b703409a WOS Scopus РИНЦ ANCAN OpenAlex

Submitted:	Mar 6, 2007
Accepted:	Apr 4, 2007
Published online:	May 9, 2007
Published print:	Jun 1, 2007

Web of science:	WOS:000247314000022
Scopus:	2-s2.0-34447311084
Elibrary:	13541586
Chemical Abstracts:	2007:706905
Chemical Abstracts (print):	147:285874
OpenAlex:	W2085808733

DB	Citing
Web of science	19
Scopus	20
Elibrary	19
OpenAlex	22