| Titre : | Preparation and properties of microspherical alumina with a magnetic core/shell structure (2009) |
| Auteurs : | Jun-Ting Feng, Auteur ; Lin, Yan-Jun, Auteur ; Feng Li, Auteur ; David G. Evans, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 48 N°2, Janvier 2009) |
| Article en page(s) : | p.692–697 |
| Note générale : | chemical engenireeng |
| Langues : | Anglais |
| Tags : | Microspherical -- Alumina |
| Résumé : | A series of Ni2+−Co2+−Fe2+−Fe3+−SO42− layered double hydroxide precursors with different Ni/Co ratios have been synthesized by a method involving separate nucleation and aging steps. After calcination at 900 °C, the corresponding Ni1-xCoxFe oxides were obtained. Vibrating sample magnetometry indicated that the Ni1-xCoxFe oxide samples not only had high specific saturation magnetization, but also low coercivity and remanence. Ni1-xCoxFe oxides showed the optimum combination of magnetic properties for x = 0.2. Silica was coated onto the surface of Ni0.8Co0.2Fe oxide particles, and the coated particles were used as magnetic cores to prepare magnetic Ni0.8Co0.2Fe oxide/SiO2/γ-Al2O3 particles by hydrolysis of aluminum isopropoxide. After repeating the hydrolysis twice more, Ni0.8Co0.2Fe oxide/SiO2/γ-Al2O3 particles with about 20 wt % Ni0.8Co0.2Fe oxide were obtained and shown to be suitable for practical applications as a magnetic catalyst or catalyst support by virtue of their efficacious magnetic properties and pore structure. |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie801098k |
