TY - JOUR
T1 - Interaction of hydrogen with extraframework cations in zeolite hosts probed by inelastic neutron scattering spectroscopy
AU - Eckert, Juergen
AU - Trouw, Frans R.
AU - Mojet, Barbara
AU - Forster, Paul
AU - Lobo, Raul
PY - 2010/1
Y1 - 2010/1
N2 - The hindered rotations of molecular hydrogen adsorbed at low loadings into a number of partially ion-exchanged zeolites A, Y and X have been studied at low temperatures with the use of inelastic neutron scattering (INS) techniques. The factors that determine the sorption sites and strength of the interaction with the host material are found to be a complex combination of the type, charge and size of the cations, their coordination to the host framework, and accessibility to the hydrogen molecule as well as the relative acidity of the framework, and lead to important criteria for the development of more effective hybrid materials for hydrogen storage. The highest barriers to rotation were found for the undercoordinated, exposed Li+ cations in LiA and in LiX. Interaction with the extra framework Cu2+ and Zn2+ cations in zeolite A is found to be noticeably stronger than with the neutral Zn- or Cu- containing clusters in metal-organic framework compounds. Our observation that binding of hydrogen in these charged frameworks is strongly enhanced relative to those that are neutral suggests an important approach to improvement of porous materials as ambient temperature hydrogen storage media.
AB - The hindered rotations of molecular hydrogen adsorbed at low loadings into a number of partially ion-exchanged zeolites A, Y and X have been studied at low temperatures with the use of inelastic neutron scattering (INS) techniques. The factors that determine the sorption sites and strength of the interaction with the host material are found to be a complex combination of the type, charge and size of the cations, their coordination to the host framework, and accessibility to the hydrogen molecule as well as the relative acidity of the framework, and lead to important criteria for the development of more effective hybrid materials for hydrogen storage. The highest barriers to rotation were found for the undercoordinated, exposed Li+ cations in LiA and in LiX. Interaction with the extra framework Cu2+ and Zn2+ cations in zeolite A is found to be noticeably stronger than with the neutral Zn- or Cu- containing clusters in metal-organic framework compounds. Our observation that binding of hydrogen in these charged frameworks is strongly enhanced relative to those that are neutral suggests an important approach to improvement of porous materials as ambient temperature hydrogen storage media.
KW - Hydrogen
KW - Neutron scattering
KW - Zeolites
UR - http://www.scopus.com/inward/record.url?scp=77953556734&partnerID=8YFLogxK
U2 - 10.1166/jnn.2010.1504
DO - 10.1166/jnn.2010.1504
M3 - Article
C2 - 20352810
AN - SCOPUS:77953556734
SN - 1533-4880
VL - 10
SP - 49
EP - 59
JO - Journal of Nanoscience and Nanotechnology
JF - Journal of Nanoscience and Nanotechnology
IS - 1
ER -