| Titre : | Effects of processing parameters on the morphology of precipitated manganese oxide powders (2009) |
| Auteurs : | Qiang Zhao, Auteur ; Shih, Wan Y., Auteur ; Shih, Wei-Heng, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 48 N°3, Février 2009) |
| Article en page(s) : | p. 1490–1494 |
| Langues : | Anglais |
| Tags : | Manganese oxide powders |
| Résumé : |
It is desirable that the surface area of catalytic materials can be controlled by adjusting the processing parameters. In this paper we report that the morphology of precipitated manganese oxide powders after 500 °C calcination is affected by the volume ratio between the manganese nitrate precursor and ammonium hydroxide and also by the concentration of the precursor solution. When a large amount of ammonium hydroxide (nominal concentration of NH4OH in the final suspension greater than 4 N) was used, the synthesized powder had plate-like particles with higher specific surface area compared to spherical particles made by a small amount of ammonium hydroxide (nominal concentration of NH4OH less than 1 N). Thinner plates were synthesized from the system with lower nominal concentration of Mn(NO3)2, resulting in even higher specific surface area. The surface area differences between these powders synthesized by different conditions decreased as the calcination temperatures increased from 500 to 900 °C because the high calcination temperatures eliminated the morphology difference among them. |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie801173e |
