LOCAL, NANOSTRUCTURES AND MICROSTRUCTURES OF MIXED-METAL OXIDE AEROGELS FOR CATA

2020-03-25 22:53:05

structure silica oxide isolated aerogel

责任者: HAIR, LM;OWENS, L;TILLOTSON, T;FROBA, M;WONG, J;THOMAS, GJ;MEDLIN, DL 单位: SANDIA NATL LABS,DEPT PHYS PROPERTIES MAT,LIVERMORE,CA 94551. 来源出处: JOURNAL OF NON-CRYSTALLINE SOLIDS, v 186, JUN 1995, p 168- 176 摘要: Sol-gel synthesis and processing have the potential to create catalytic sites atomically isolated in the aerogel framework. V or Cu were incorporated during the solution chemistry into silica aerogels. Extrended X-ray absorption fine structure and X-ray absorption near edge structure were employed to determine that copper is present as an oxide and probably isolated in the silica matrix, while vanadium is present as V2O4 and V2O5. High resolution transmission electron microscopy and selected area diffraction were used to elucidate the characteristics of the aerogel structure itself, including the diameter of the chains, as well as to look for phase separation and crystallinity of the active metal oxide. It was found that the metals were highly dispersed in the silica aerogel, even after oxidation and reaction treatments. 关键词: CIRCULATION TIME; BODY DISTRIBUTION; PROTEIN A; POLYSTYRENE NANOPARTICLE;