โ Scribed by Md.Azhar Uddin; Takayuki Komatsu; Tatsuaki Yashima
No coin nor oath required. For personal study only.
The catalytic activity of framework iron in MFI-type ferrisilicate was studied. The incorporation of Fe"+ ions in the tetrahedral framework of MFI-type ferris&ate was investigated by means of Miissbauer spectroscopy. The derived Miissbauer parameter at room temperature clearly indicated the presence of Fe'+ ions in tetrahedral lattice sites. The catalytic activity of ferrisilicate was tested for the oxidation of CO with 0, at 673 K and was compared with the activities of iron-oxideimpregnated silicalite (FeO,/Sil) and Fe ion-exchanged ZSM-5 (FeZSM-5). The CO oxidation activity of the tetrahedrally coordinated Fe3+ in ferrisilicate was much lower than that of octahedrally coordinated Fe'+ in FeO,/Sil and Fe"+ in ionexchange sites of FeZSM-5. Kinetic studies were performed on these catalysts at 623 K. On ferrisilicate, the reaction orders for CO and 0, were 1.0 and 1.1, respectively, while on FeO, and FeZSM-5 the reaction orders were 1.3 and 1.2 for CO, respectively, and near zero for Oa in both cases. For CO oxidation, both the activity and reaction mechanism on ferrisilicate differed markedly from those on FeO,/Sil and FeZSM-5.
๐ SIMILAR VOLUMES
The textural structure and the surface property of activated carbon were selectively modified by KMnO 4 oxidation. The activated carbon treated by KMnO 4 oxidation in an acidic solution showed greatly enhanced H 2 O 2 production by hydroxylamine oxidation due to the creation of more surface quinoid