Formation of catalytically active copper and nickel nanoparticles in natural zeolites; 4th FEZA Conference, Collège de France, Paris, France, september, 2-6, 2008
| Parent link: | 4th FEZA Conference, Collège de France, Paris, France, september, 2-6, 2008.— 2008.— PI-C05 |
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| অন্যান্য লেখক: | , , , , |
| সংক্ষিপ্ত: | Structure, thermostability and catalytic properties of copper and nickel nanoparticles in natural and synthetic zeolites have been studied using methods of XRD, elemental analysis, UV-visible spectroscopy, MAS NMR, TEM and catalytic testing. Different states of Cu have been identified by UV-Vis spectroscopy: Cu+ and Cu2+ ions, O-Cu-O and Cu-O-Cu complexes and Cu nanoparticles. Measurements of synthetic zeolites showed that shape and position of plasma resonance band depend on the acidity of zeolite supports. The most acid mordenites with Si/Al≈7-10 prevents formation of copper nanoparticles while Cu2+ is reduced to Cu+ and few atomic Cun clusters. Less acid erionite, clinoptilolite and mordenites with high Si/Al ratio promote formation of Cu nanoparticles. For Ni-exchanged zeolites spectra typical for Ni(H2O)62+ are observed. The spectra changed with increasing temperature due to dehydration of Ni2+ coordination sphere and replacement of H2O ligand molecules by oxygen atoms of zeolite framework. The catalytic experiments demonstrate that the temperature of beginning of hydrocarbons conversion starts in 170-250°C range, depending on the composition of the catalyst. The complete conversion can be observed for all zeolites, depending (probably) on Si/Al ratio of the zeolite matrix. No destruction of crystalline structure was observed from XRD and 27Al MAS NMR spectra under conditions used for catalytic tests. В фонде НТБ ТПУ отсутствует |
| ভাষা: | ইংরেজি |
| প্রকাশিত: |
2008
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| বিষয়গুলি: | |
| বিন্যাস: | গ্রন্থের অধ্যায় |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=599112 |