Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties
Titania gels T a and T b were precipitated from TiCl 4 at pH 3.0 and 9.0, respectively, using ammonia solution. Calcination products were obtained by the thermal treatment of the gels at 300, 400, 600, 750 and 1000°C, respectively. Thermal analysis, X-ray diffraction and FT-IR spectroscopy demonstra...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SAGE Publishing
2001-03-01
|
| Series: | Adsorption Science & Technology |
| Online Access: | https://doi.org/10.1260/0263617011494051 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1841564441506742272 |
|---|---|
| author | Th. El-Nabarawy A.M. Youssef S.A. Sayed Ahmed |
| author_facet | Th. El-Nabarawy A.M. Youssef S.A. Sayed Ahmed |
| author_sort | Th. El-Nabarawy |
| collection | DOAJ |
| description | Titania gels T a and T b were precipitated from TiCl 4 at pH 3.0 and 9.0, respectively, using ammonia solution. Calcination products were obtained by the thermal treatment of the gels at 300, 400, 600, 750 and 1000°C, respectively. Thermal analysis, X-ray diffraction and FT-IR spectroscopy demonstrated that the anatase → rutile transformation commenced when T a was calcined at 400°C, with the rutile form predominating when calcination was conducted at 600°C. Calcination at 750°C or 1000°C was associated with complete anatase → rutile conversion. The calcination product of T b at 400°C was pure anatase, transformation to rutile taking place above this temperature and predominating at 600°C. Rutile was the sole phase present when T b was calcined at 750°C. Vanadia/titania catalysts were obtained by impregnating T a and T b with an aqueous solution of NH 4 VO 4 of concentration sufficient to obtain samples containing 4.0, 6.0, 8.0 or 12.0 wt% V 2 O 5 . The calcination products at 400°C and 600°C were characterized by thermal analysis, X-ray diffraction, FT-IR spectroscopy, electronic spectral analysis and magnetic susceptibility measurements. The presence of vanadium enhanced the anatase → rutile transformation. The measured X-ray diffraction lines and FT-IR peaks indicated the existence of vanadium as a separate oxide, mainly V 2 O 5 . However, the electronic spectra and magnetic susceptibility measurements predicted the possible existence of a V 4+ species. |
| format | Article |
| id | doaj-art-0c9a31c699214b778c158d92e9102af8 |
| institution | Kabale University |
| issn | 0263-6174 2048-4038 |
| language | English |
| publishDate | 2001-03-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Adsorption Science & Technology |
| spelling | doaj-art-0c9a31c699214b778c158d92e9102af82025-01-02T22:39:32ZengSAGE PublishingAdsorption Science & Technology0263-61742048-40382001-03-011910.1260/0263617011494051Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural PropertiesTh. El-Nabarawy0A.M. Youssef1S.A. Sayed Ahmed2 Laboratory of Surface Chemistry and Catalysis, National Research Centre, Dokki, Cairo, Egypt Faculty of Science, Mansoura University, Mansoura, Egypt Laboratory of Surface Chemistry and Catalysis, National Research Centre, Dokki, Cairo, EgyptTitania gels T a and T b were precipitated from TiCl 4 at pH 3.0 and 9.0, respectively, using ammonia solution. Calcination products were obtained by the thermal treatment of the gels at 300, 400, 600, 750 and 1000°C, respectively. Thermal analysis, X-ray diffraction and FT-IR spectroscopy demonstrated that the anatase → rutile transformation commenced when T a was calcined at 400°C, with the rutile form predominating when calcination was conducted at 600°C. Calcination at 750°C or 1000°C was associated with complete anatase → rutile conversion. The calcination product of T b at 400°C was pure anatase, transformation to rutile taking place above this temperature and predominating at 600°C. Rutile was the sole phase present when T b was calcined at 750°C. Vanadia/titania catalysts were obtained by impregnating T a and T b with an aqueous solution of NH 4 VO 4 of concentration sufficient to obtain samples containing 4.0, 6.0, 8.0 or 12.0 wt% V 2 O 5 . The calcination products at 400°C and 600°C were characterized by thermal analysis, X-ray diffraction, FT-IR spectroscopy, electronic spectral analysis and magnetic susceptibility measurements. The presence of vanadium enhanced the anatase → rutile transformation. The measured X-ray diffraction lines and FT-IR peaks indicated the existence of vanadium as a separate oxide, mainly V 2 O 5 . However, the electronic spectra and magnetic susceptibility measurements predicted the possible existence of a V 4+ species.https://doi.org/10.1260/0263617011494051 |
| spellingShingle | Th. El-Nabarawy A.M. Youssef S.A. Sayed Ahmed Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties Adsorption Science & Technology |
| title | Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties |
| title_full | Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties |
| title_fullStr | Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties |
| title_full_unstemmed | Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties |
| title_short | Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties |
| title_sort | physicochemical and catalytic properties of vanadia titania catalysts i structural properties |
| url | https://doi.org/10.1260/0263617011494051 |
| work_keys_str_mv | AT thelnabarawy physicochemicalandcatalyticpropertiesofvanadiatitaniacatalystsistructuralproperties AT amyoussef physicochemicalandcatalyticpropertiesofvanadiatitaniacatalystsistructuralproperties AT sasayedahmed physicochemicalandcatalyticpropertiesofvanadiatitaniacatalystsistructuralproperties |