Thermodynamic study of water adsorption in high-silica zeolites
Article Abstract:
The combined use of microcalorimetric and computational approaches are adopted to describe the mechanism of [H.sub.2] interaction with the acidic sites located within the proton-exchanged zeolites nanocavities, of both Lewis and Bronsted nature. The adsorption experimental enthalpies are compared to ab initio computed binding energies of [H.sub.2]O interacting with model sites simulating Lewis and Bronsted acidic sites and a variety of Si-OH species, either H-bonding interacting or isolated.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2006
User Contributions:
Comment about this article or add new information about this topic:
Molecular water on exposed A[l.sup.3+] cations is a source of acidity in silicoaluminas
Article Abstract:
A study using infrared spectroscopy and ab initio calculations provided evidence about the remarkable acidic nature of molecular water adsorbed at the surface of mesoporous MCM-41 silicoaluminas (MSA) with a ratio of Si/Al = 25. OH stretching and HOH bending modes of water adsorbed on coordinatively unsaturated Al ions at the surface of mesoporous version of silicoaluminas were detected for the first time using CO as a probe.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2006
User Contributions:
Comment about this article or add new information about this topic:
Can Cu+-exchanged zeolites store molecular hydrogen? An ab-initio periodic study compared with low temperature FTIR
Article Abstract:
Using the periodic CRYSTAL03 computer code with Hartree-Fock and the hybrid B3LYP Hamiltonians to characterize the structures and energetics of the Cu+ ion sitting preference and interaction with H2, Cu+-exchanges Si/Al 11:1 chabatize is studies ab initio. Chabatize has been selected because its small unit cell allows fully ab initio periodic calculations with good basis sets to be performed on commodity personal computers.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2004
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Theoretical study of NH3 adsorption on Fe(110) and Fe(111) surfaces. Does the ring compound [(CH3)2GaNH2]3 form during MOVPE of gallium nitride? Investigations via density functional and reaction rate theories
- Abstracts: Molecular dynamics study on the glass transition in Ca0.4K0.6(NO3)(sub 1.4). Ab initio molecular dynamics simulations of NO reactivity on the CaO(001) surface
- Abstracts: Limitations of atom-centered dielectric functions in implicit solvent models. Dielectric properties of the bR membrane
- Abstracts: Counterion effect on the thermodynamics of micellization of alkyl sulfates. Synthetic macroporous silicas with multilamellar structure
- Abstracts: Selectivity of the chemisorptions of vinylacetic acid on the Si (001) 2x1 surface. Acid-base characterization of aluminum oxide surfaces with XPS