| Autor: |
Yunes S; Micromeritics Instrument Corporation, 4356 Communications Drive, Norcross, GA 30093, USA. Simon.Yunes@micromeritics.com., Vicente MÁ; GIR QUESCAT-Departamento de Química Inorgánica, Universidad de Salamanca, 37008 Salamanca, Spain. mavicente@usal.es., Korili SA; INAMAT-Departamento de Ciencias, Universidad Pública de Navarra, 31006 Pamplona, Spain. sofia.korili@unavarra.es., Gil A; INAMAT-Departamento de Ciencias, Universidad Pública de Navarra, 31006 Pamplona, Spain. andoni@unavarra.es. |
| Jazyk: |
angličtina |
| Zdroj: |
Materials (Basel, Switzerland) [Materials (Basel)] 2019 Jun 13; Vol. 12 (12). Date of Electronic Publication: 2019 Jun 13. |
| DOI: |
10.3390/ma12121915 |
| Abstrakt: |
The effect of high pressure on the reducibility and dispersion of oxides of Co and Fe supported on γ-Al 2 O 3 , SiO 2 , and TiO 2 has been studied. The catalysts, having a nominal metal content of 10 wt.%, were prepared by incipient wetness impregnation of previously calcined supports. After drying at 60 °C for 6 h and calcination at 500 °C for 4 h, the catalysts were reduced by hydrogen at two pressures, 1 and 25 bar. The metal reduction was studied by temperature-programmed reduction up to 750 °C at the two pressures, and the metal dispersion was measured by CO chemisorption at 25 °C, obtaining values between 1% and 8%. The physicochemical characterization of these materials was completed by means of chemical analysis, X-ray diffraction, N 2 adsorption-desorption at -196 °C and scanning electron microscopy. The high pressure lowered the reduction temperature of the metal oxides, improving their reducibility and dispersion. The metal reducibility increased from 42%, in the case of Fe/Al 2 O 3 (1 bar), to 100%, in the case of Fe/TiO 2 (25 bar). |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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