Zobrazeno 1 - 10
of 282
pro vyhledávání: '"Harry Pfeifer"'
Autor:
Jörg Kärger, Harry Pfeifer
Any catalyzed reaction proceeds in parallel with a variety of molecular mass transfer phenomena, so that in many cases the observed activities and product distributions are linked to the diffusional behavior of the reactant, intermediate, and product
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1b84f8e71d6ac1fb60f7b1897e821c6b
https://doi.org/10.1201/9781003067238-2
https://doi.org/10.1201/9781003067238-2
Publikováno v:
Scopus-Elsevier
We present a 13C MAS NMR study on the adsorption of methane on HY zeolite. These investigations were carried out at temperatures ranging from 295 K to 135 K and at loadings up to 105 methane molecules per unit cell. Up to three signals appear in the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::20e14bf1e6e2525a869246cccb4775c6
https://doi.org/10.1524/zpch.2001.215.1.063
https://doi.org/10.1524/zpch.2001.215.1.063
Publikováno v:
Microporous and Mesoporous Materials. 40:1-7
EPR spectra of H-ZSM-5 activated at 773 and 1073 K for non-treated and hydrothermally treated samples were measured without loading and loaded with two molecules of NO per three aluminum atoms of the zeolite framework. In accordance with the literatu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7941b1fc68004908100b4e3f5a0a19a4
https://doi.org/10.1016/s1387-1811(00)00232-8
https://doi.org/10.1016/s1387-1811(00)00232-8
Publikováno v:
Microporous and Mesoporous Materials. :341-347
The adsorption of trimethylgallium on H-zeolites is accompanied by the conversion of methyl groups into methane. A detailed NMR and IR spectroscopic study of the adsorption of methane and trimethylgallium on zeolite HY is provided in the present cont
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::72fe9693d36efe329bd9a5d6ae997c2a
https://doi.org/10.1016/s1387-1811(99)00232-2
https://doi.org/10.1016/s1387-1811(99)00232-2
Autor:
Harry Pfeifer
Publikováno v:
Magnetic Resonance in Chemistry. 37:S154-S159
A short history of nuclear magnetic resonance spectroscopy is given. Emphasis has been laid on the beginning of NMR studies in Germany, especially in Leipzig, where Felix Bloch received his doctor's degree in 1928 as a student of Werner Heisenberg. T
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f651563fdb997d8a10a2a5733c854b73
https://doi.org/10.1002/(sici)1097-458x(199912)37:133.0.co
https://doi.org/10.1002/(sici)1097-458x(199912)37:13
Publikováno v:
Microporous and Mesoporous Materials. 22:289-295
The pulsed field gradient NMR technique is applied to study water diffusivity in natural chabazite. Information about diffusion anisotropy is deduced from both single-crystallite measurements and analysing the shape of the NMR spin–echo attenuation
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ee517754b96907d449be963a831c47bd
https://doi.org/10.1016/s1387-1811(98)00083-3
https://doi.org/10.1016/s1387-1811(98)00083-3
Publikováno v:
Microporous Materials. 6:341-347
The interaction of surface hydroxyl groups in zeolites with adsorbed C 2 Cl 4 molecules was investigated by lowtemperature 1 H MAS NMR and FTIR spectroscopy. It could be shown that the induced 1 H NMR chemical shift Δδ of free surface hydroxyl grou
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::eabd46337e0b931b07a76b491ef42692
https://doi.org/10.1016/0927-6513(96)00038-7
https://doi.org/10.1016/0927-6513(96)00038-7
Autor:
Reinhold Haberlandt, Jörg Kärger, Karl Heinzinger, Harry Pfeifer, Siegfried Fritzsche, Max Wolfsberg
Publikováno v:
Chemical Physics Letters. 242:361-366
Diffusion of methane in LTA type zeolites has been calculated from molecular dynamics simulations. Taking into account the polarization interaction of the exchangeable cations in the zeolite NaCaA with the methane molecules, the self-diffusion coeffi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::52ec81603a4044fdf5e2e5b23b2c60cb
https://doi.org/10.1016/0009-2614(95)00744-o
https://doi.org/10.1016/0009-2614(95)00744-o
Publikováno v:
Microporous Materials. 4:141-147
13 C Magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopic measurements were carried out in order to investigate the interaction between Lewis acid sites in H-ZSM-5 and adsorbed carbon monoxide. A new measure for the “overall” L
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::23f2074fa19a80c054fd0157a414a780
https://doi.org/10.1016/0927-6513(94)00092-a
https://doi.org/10.1016/0927-6513(94)00092-a
Publikováno v:
Zeitschrift für Naturforschung A. 50:388-394
After reviewing the basic principles of zero-field NMR spectroscopy at high magnetic fields (ZFHF NMR) as introduced by Robert Tycko, a 2-dimensional extension of this method is described which enhances its sensitivity by at least one order of magnit
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c432ba5163c673c0cb9f22a531ac28f2
https://doi.org/10.1515/zna-1995-4-511
https://doi.org/10.1515/zna-1995-4-511