Effect of redox treatments on activation and deactivation of gold nanospecies supported on mesoporous silica in CO oxidation
| Parent link: | Fuel Vol. 110 : IMCCRE 2012 “International-Mexican Congress on Chemical Reaction Engineering”.— 2013.— [P. 40-47] |
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| Other Authors: | , , , , , , |
| Summary: | Title screen The influence of pretreatments with He, O2 and H2 on the physicochemical and catalytic properties of gold supported on hexagonal mesoporous silica (HMS) has been studied by a variety of methods including: XPS, TPR, N2 sorption, UV-visible spectroscopy, FTIR and catalytic testing. The investigations show supported gold to form different states under redox treatments: Au3+ and Au+ ions, neutral and partly charged gold clusters and metal nanoparticles of different sizes. Reducing pretreatments increase the catalytic activity of the samples; while oxidative treatments deactivate the catalyst. Catalytic tests show several regions of the reduced samples with various catalytic behaviours: 20-200 °C, 200-400 °C and >400 °C; this situation is explained by the co-existence of gold active sites of different types. A comparative analysis among spectroscopic and catalytic data allows suggesting clusters to be responsible for the activity in the low-temperature region (<200 °C); neutral Aun clusters are active in the range 200-400 °C; and gold nanoparticles may catalyze high-temperature CO oxidation. Au3+ ions are inactive in this process. Режим доступа: по договору с организацией-держателем ресурса |
| Published: |
2013
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1016/j.fuel.2012.09.064 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=636298 |