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Catalytic properties of transition metal salts immobilized on nanoporous silica polyamine composites II: Hydrogenationстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Allen J., Rosenberg E., Karakhanov E., Kardashev S.V., Maximov A., Zolotukhina A.
- Журнал: Applied Organometallic Chemistry
- Том: 25
- Номер: 4
- Год издания: 2011
- Издательство: John Wiley & Sons Inc.
- Местоположение издательства: United States
- Первая страница: 245
- Последняя страница: 254
- DOI: 10.1002/aoc.1749
- Аннотация: The transition metal compounds Pd(OAc) 2, RhCl 3·4H 2O and RuCl 3 · nH 2O were adsorbed onto the nanoporous silica polyamine composite (SPC) particles (150-250 μm), WP-1 [poly(ethyleneimine) on amorphous silica], BP-1 [poly(allylamine) on amorphous silica], WP-2 (WP-1 modified with chloroacetic acid) and BP-2 (BP-1 modified with chloroacetic acid). Inductively coupled plasma-atomic emission spectrometry analysis of the dried samples after digestion indicated metal loadings of 0.4-1.2 mmol g -1 except for RhCl 3·4H 2O on BP-2 which showed a metal loading of only 0.1 mmol g -1. The metal loaded composites were then screened as hydrogenation catalysts for the reduction of 1-octene, 1-decene, 1-hexene and 1, 3-cyclohexadiene at a hydrogen pressure of 5 atm in the temperature range of 50-90 °C. All 12 combinations of SPC and transition metal compound proved active for the reduction of the terminal olefins, but isomerization to internal alkenes was competitive in all cases. Under these conditions, selective hydrogenation of 1,3-cyclohexadiene to cyclohexene was observed with some of the catalysts. Turnover frequencies were estimated for the hydrogenation reactions based on the metal loading and were in some cases comparable to more conventional heterogeneous hydrogenation catalysts. Examination of the catalysts before and after reaction with X-ray photoelectron spectroscopy and transmission electron microscopy revealed that, in the cases of Pd(OAc) 2 on WP-2, BP-1 and BP-2, conversion of the surface-ligand bound metal ions to metal nano-particles occurs. This was not the case for Pd(OAc) 2 on WP-1 or for RuCl 3 · nH 2O and RhCl 3· 4H 2O on all four composites. The overall results are discussed in terms of differences in metal ion coordination modes for the composite transition-metal combinations. Suggested ligand interactions are supported by solid state CPMAS 13C NMR analyses and by analogy with previous structural investigations of metal binding modes on these composite materials. © 2011 John Wiley & Sons, Ltd.
- Добавил в систему: Максимов Антон Львович