| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 55746 | Catalysis Today | 2011 | 7 Pages |
The Ce–Zr mixed oxides have been examined as supports for platinum and gold in oxidation of ethanol and toluene. A weight ratio of Ce/Zr in the synthesized supports was 1/1. Two supported noble metals with a different loading (2.5 and 0.3 wt.%) were compared to each other as well as to selected industrial catalysts (HHC-5557 and VOC-1544). Whatever the metal content was, Pt catalysts were always more active in oxidation of ethanol and toluene than Au catalysts. Better reductive capability of platinum was confirmed by H2-TPR profiles and a higher activity of platinum may also be linked to changes in surface basic properties (a higher amount of basic centers) illustrated by CO2-TPD profiles. Deposition of gold on Ce–Zr mixed oxide resulted in a formation of certain amounts of crystalline Au phase detected by X-ray diffraction while the deposition of platinum did not produce any crystalline Pt phase. As observed by FE-SEM, part of Au was well dispersed but significant amount of Au was present as inactive crystals. Platinum catalysts were comparable or even more active than industrial catalysts (50% conversion of ethanol was achieved with 2.5Pt/CeZr(1) at 99 °C). On the other hand, gold catalysts proved the best selectivity in oxidation of ethanol.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (172 K)Download as PowerPoint slideHighlights► Different drying during preparation of the support (Ce0.5Zr0.5O2) by sol–gel method slightly alters the pore-size distribution and influence the activity of catalytic material in oxidation processes. ► Au and Pt catalysts supported on Ce0.5Zr0.5O2 are remarkably active in the oxidation of toluene and ethanol, respectively. ► Supported platinum is more active than gold in the oxidation of toluene and ethanol, while gold is more selective.
