| Autor: |
Anna Beltzung, Mark A. Newton, Maarten Nachtegaal, Hua Wu, Giuseppe Storti, Massimo Morbidelli |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| Předmět: |
|
| Zdroj: |
APL Materials, Vol 6, Iss 10, Pp 100704-100704-15 (2018) |
| Druh dokumentu: |
article |
| ISSN: |
2166-532X |
| DOI: |
10.1063/1.5046552 |
| Popis: |
In this work, the synthesis of a stable supported Pd catalyst by aggregation of colloidal particles (CPs) of polyacrylonitrile (PAN) containing the noble metal is discussed. The metal is initially incorporated during the polymerization reaction (0.5 wt. %) and results to be well embedded inside the polymeric structure and anchored to the nitrogen atom of acrylonitrile. Moreover, aiming to provide free access towards the catalyst active sites, a KOH-activated heat treatment was performed on the PAN CP aggregates, thus creating pore sizes between 0.7 and 5 nm with surface area SBET = 1150 m2/g. After the harsh heat treatment, the amount of Pd remaining in the pyrolyzed polymer is 2.8 wt. %, as measured by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), which then corresponds to a total weight loss of 83% (assuming no loss of Pd). This result indicates a remarkable stability of Pd inside the polymer structure and that minimal Pd leaching can be expected during the catalyst use. X-ray absorption spectroscopic studies of pyrolyzed Pd-containing PAN and following extended X-ray absorption fine structure fitting showed no sign of bulk Pd(0), while a dominant proportion of Pd is present as dispersed Pd carbides. These results are consistent with the data obtained using X-ray absorption near edge structure. Finally, the catalyst was tested on a Suzuki coupling in the liquid phase and showed good activity, hence proving the accessibility of the active sites to reactants. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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