Quantitative determination of residual silver distribution in nanoporous gold and its influence on structure and catalytic performance
| Autor: | Daniele Zanaga, Andreas Rosenauer, Arne Wittstock, Marco Schowalter, Karsten Thiel, Sara Bals, Anastasia Lackmann, Christoph Mahr, Martin Schwan, Paromita Kundu |
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| Přispěvatelé: | Publica |
| Rok vydání: | 2017 |
| Předmět: |
quantitative EDXS tomography
Methyl formate Alloy Inorganic chemistry nanoporous gold 02 engineering and technology engineering.material 010402 general chemistry Residual 01 natural sciences Chemical reaction Catalysis silver cluster chemistry.chemical_compound menthol oxidation Physical and Theoretical Chemistry Porosity Chemistry Nanoporous Physics 021001 nanoscience & nanotechnology residual silver 0104 chemical sciences co oxidation engineering Methanol 0210 nano-technology |
| Zdroj: | Journal of catalysis |
| ISSN: | 0021-9517 |
| DOI: | 10.1016/j.jcat.2017.05.002 |
| Popis: | Large efforts have been made trying to understand the origin of the high catalytic activity of dealloyed nanoporous gold as a green catalyst for the selective promotion of chemical reactions at low temperatures. Residual silver, left in the sample after dealloying of a gold-silver alloy, has been shown to have a strong influence on the activity of the catalyst. But the question of how the silver is distributed within the porous structure has not finally been answered yet. We show by quantitative energy dispersive X-ray tomography measurements that silver forms clusters that are distributed irregularly, both on the surface and inside the ligaments building up the porous structure. Furthermore, we find that the role of the residual silver is ambiguous. Whereas CO oxidation is supported by more residual silver, methanol oxidation to methyl formate is hindered. Structural characterisation reveals larger ligaments and pores for decreasing residual silver concentration. |
| Databáze: | OpenAIRE |
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