Yıl 2010, Cilt: 5 Sayı : 5 Sayfalar 826 - 831 2010-12-31
The Influence of Active Component Acidity on the Spreading of Cerium Oxide on Silica Surface
The Influence of Active Component Acidity on the Spreading of Cerium Oxide on Silica Surface
A.f.a. Mohmed,H.m. İsmail
15 261

The spreading of active component of cerium oxide (ceria, CeO2) supported on silica (SiO2) depends on the acidity medium and pretreatment conditions. The acidity medium of the impregnation solution (normally of ammonium cerium (IV) nitrate) affects both the support (SiO2) and the nature of the cerium species in solution.Supported ceria on silica catalysts have been prepared using impregnation solution with different acidity levels (pH 2, 4 and 8). The impregnation solution of ammonium cerium (IV) nitrate yielded final loading containing 2 – 8 wt% of CeO2 on SiO2 surface. The solutions were stirring for 3 hrs; the excess water was slowly evaporated at 100°C. Furthermore, the impregnated solution was further dried at 120°C for 24 h. The products thus obtained were calcined at 700 °C for 2 h in static atmosphere of air. Thermal analysis of ammonium cerium (IV) nitrate revealed that CeO2 formed at 700oC. Moreover, X-ray powder diffractogram (XRD) for SiO2, supported CeO2 and different loading levels (2 – 8 wt% of CeO2 on SiO2 surface) catalysts were investigated.The investigation results revealed that the formation of CeO2 crystallites are spreading on the SiO2 surface at a loading levels of 2 wt% CeO2, at pH=2. Whereas, spreading further for 4wt% CeO2, at pH=4 and highly spreading at 8 wt% CeO2, at pH=8. Consequently, poor spreading of CeO2 on the SiO2 surface at high acidity medium (low pH=2). While, at low acidity medium (high pH=8) active phase-support interaction was strongest and high spreading was found

Anahtar Kelimeler

Birincil Dil tr
Konular
Yayımlanma Tarihi 31 Aralık 2010
Bölüm Makaleler
Yazarlar
Tarihler

Yayımlanma Tarihi : 31 Aralık 2010


Makalenin Yazarları
A.f.a. Mohmed
H.m. İsmail