Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids
The surface and catalytic properties of Co 3 O 4 /Al 2 O 3 solids treated with different proportions of MoO 3 were investigated, the extent of MoO 3 added varying between 0.50 mol% and 5.00 mol% (0.63–5.9 wt%). The pure sample was prepared by thermal decomposition at 600°C of aluminium hydroxide imp...
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| Format: | Article |
| Language: | English |
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SAGE Publishing
2000-07-01
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| Series: | Adsorption Science & Technology |
| Online Access: | https://doi.org/10.1260/0263617001493620 |
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| author | A.M. Ghozza G.A. El-Shobaky G.M. Mohamed |
| author_facet | A.M. Ghozza G.A. El-Shobaky G.M. Mohamed |
| author_sort | A.M. Ghozza |
| collection | DOAJ |
| description | The surface and catalytic properties of Co 3 O 4 /Al 2 O 3 solids treated with different proportions of MoO 3 were investigated, the extent of MoO 3 added varying between 0.50 mol% and 5.00 mol% (0.63–5.9 wt%). The pure sample was prepared by thermal decomposition at 600°C of aluminium hydroxide impregnated with a calculated amount of Co(NO 3 ) 2 dissolved in the least amount of distilled water. The MoO 3 -treated samples were prepared by thermal decomposition at 600°C of aluminium hydroxide treated with different proportions of ammonium molybdate followed by treatment with Co(NO 3 ) 2 solution. The crystalline phases produced by thermal treatment of the pure and treated samples precalcined at 600°C were characterized using an XRD technique. The surface and catalytic properties of the various catalysts were studied using nitrogen adsorption at −196°C and CO oxidation by O 2 at 100–150°C. The results obtained revealed that molybdena treatment of the Co 3 O 4 /Al 2 O 3 solids followed by precalcination at 600°C resulted in a decrease in the degree of crystallinity of the Co 3 O 4 phase produced. This treatment effected a progressive small increase in the specific surface area of the treated solids (ca. 10%). However, the catalytic activity was found to be increased considerably by increasing the amount of MoO 3 added (184%), reaching a maximum limit at 1.00 mol% MoO 3 . The activation energies of the catalytic reaction calculated for both the pure and MoO 3 -treated solids suggested that MoO 3 treatment did not modify the energetic nature of the active sites (surface cobalt species) but increased their concentration. |
| format | Article |
| id | doaj-art-3c7bb8a0a8aa4207b2370d24bb12b050 |
| institution | Kabale University |
| issn | 0263-6174 2048-4038 |
| language | English |
| publishDate | 2000-07-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Adsorption Science & Technology |
| spelling | doaj-art-3c7bb8a0a8aa4207b2370d24bb12b0502025-01-03T00:10:31ZengSAGE PublishingAdsorption Science & Technology0263-61742048-40382000-07-011810.1260/0263617001493620Surface and Catalytic Properties of MoO-Treated CoO/AlO SolidsA.M. Ghozza0G.A. El-Shobaky1G.M. Mohamed2 Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt Department of Physical Chemistry, National Research Centre, Dokki, Cairo, Egypt Department of Physical Chemistry, National Research Centre, Dokki, Cairo, EgyptThe surface and catalytic properties of Co 3 O 4 /Al 2 O 3 solids treated with different proportions of MoO 3 were investigated, the extent of MoO 3 added varying between 0.50 mol% and 5.00 mol% (0.63–5.9 wt%). The pure sample was prepared by thermal decomposition at 600°C of aluminium hydroxide impregnated with a calculated amount of Co(NO 3 ) 2 dissolved in the least amount of distilled water. The MoO 3 -treated samples were prepared by thermal decomposition at 600°C of aluminium hydroxide treated with different proportions of ammonium molybdate followed by treatment with Co(NO 3 ) 2 solution. The crystalline phases produced by thermal treatment of the pure and treated samples precalcined at 600°C were characterized using an XRD technique. The surface and catalytic properties of the various catalysts were studied using nitrogen adsorption at −196°C and CO oxidation by O 2 at 100–150°C. The results obtained revealed that molybdena treatment of the Co 3 O 4 /Al 2 O 3 solids followed by precalcination at 600°C resulted in a decrease in the degree of crystallinity of the Co 3 O 4 phase produced. This treatment effected a progressive small increase in the specific surface area of the treated solids (ca. 10%). However, the catalytic activity was found to be increased considerably by increasing the amount of MoO 3 added (184%), reaching a maximum limit at 1.00 mol% MoO 3 . The activation energies of the catalytic reaction calculated for both the pure and MoO 3 -treated solids suggested that MoO 3 treatment did not modify the energetic nature of the active sites (surface cobalt species) but increased their concentration.https://doi.org/10.1260/0263617001493620 |
| spellingShingle | A.M. Ghozza G.A. El-Shobaky G.M. Mohamed Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids Adsorption Science & Technology |
| title | Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids |
| title_full | Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids |
| title_fullStr | Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids |
| title_full_unstemmed | Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids |
| title_short | Surface and Catalytic Properties of MoO-Treated CoO/AlO Solids |
| title_sort | surface and catalytic properties of moo treated coo alo solids |
| url | https://doi.org/10.1260/0263617001493620 |
| work_keys_str_mv | AT amghozza surfaceandcatalyticpropertiesofmootreatedcooalosolids AT gaelshobaky surfaceandcatalyticpropertiesofmootreatedcooalosolids AT gmmohamed surfaceandcatalyticpropertiesofmootreatedcooalosolids |