| Autor: |
A. A. El-Hendawy, Waleed M. Shaheen |
| Rok vydání: |
2009 |
| Předmět: |
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| Zdroj: |
Open Chemistry, Vol 7, Iss 4, Pp 780-786 (2009) |
| ISSN: |
2391-5420 |
| DOI: |
10.2478/s11532-009-0062-7 |
| Popis: |
The effects of doping with CeO2 and calcination temperature on the physicochemical properties of the NiO/Al2O3 system have been investigated using DTA, XRD, nitrogen adsorption measurements at −196°C and decomposition of H2O2 at 30–50°C. The pure and variously doped solids were subjected to heat treatment at 300, 400, 700, 900 and 1000°C. The results revealed that the specific surface areas increased with increasing calcination temperature from 300 to 400°C and with doping of the system with CeO2. The pure and variously doped solids calcined at 300 and 400°C consisted of poorly crystalline NiO dispersed on γ-Al2O3. Heating at 700°C resulted in formation of well crystalline NiO and γ-Al2O3 phases beside CeO2 for the doped solids. Crystalline NiAl2O4 phase was formed starting from 900°C. The degree of crystallinity of NiAl2O4 increased with increasing the calcination temperature from 900 to 1000°C. An opposite effect was observed upon doping with CeO2. The NiO/Al2O3 system calcined at 300 and 400°C has catalytic activity higher than individual NiO obtained at the same calcination temperatures. The catalytic activity of NiO/Al2O3 system increased, progressively, with increasing the amount of CeO2 dopant and decreased with increasing the calcination temperature. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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