Nanostructural Characterizations Of Hydrogen-permselective Si-co-o Membranes By Transmission Electron Microscopy

摘要

Nanostructural characterizations of liquid metal-organic precursors-derived cobalt-doped amorphous silica (Si-Co-O) membranes supported on a mesoporous anodic alumina capillary (MAAC) tube were performed to study their unique high-temperature hydrogen gas permeation properties. Cross-sectional scanning transmission electron microscopy images and selected-area electron diffraction patterns indicated that the metal cobalt and the different oxidation states of cobalt oxides (CoO and Co_3O_4) nanocrystallites having a size range of 5-20 nm were in situ formed in the mesopore channels of the MAAC tube. In addition, high-resolution transmission electron microscopy micrographs and electron energy loss spectroscopy elemental mapping images indicated that the highly dense Co-doped amorphous Si-O formed within the mesopore channels of the MAAC tube. These nanostructural features could contribute to the hydrogen-selective permeation properties observed for the membranes.