ausblenden:
Schlagwörter:
nanocomposite; mesoporous; alumina; carbon; cellulose
Carbon
Zusammenfassung:
Highly ordered mesoporous carbon-alumina nanocomposites (OMCA) have been for the first time synthesized by multi-component co-assembly method followed by pyrolysis at a high temperature. In this synthesis, resol and aluminum sol were respectively used as the carbon and alumina precursors and triblock copolymer F127 as the template. N2-adsorption, X-ray diffraction, and transmission electron microscopy revealed that, with an increase of the alumina content in the nanocomposite from 11 to 48 wt %, the pore size increased from 2.9 to 5.0 nm while the ordered mesoporous structure remained well. Further increasing the alumina content to 53 wt % resulted in wormhole-like structure although the pore size distribution was still narrow. The nanocomposite walls are composed of continuous carbons and amorphous aluminas, which allows the ordered mesostructure preserved well even after the removal of aluminas by HF etching or removal of carbons by calcinations in air. The OMCA nanocomposites exhibited good thermostability until 1000 ºC, above which the ordered mesostructure partially collapsed associated with the phase transformation from the amorphous alumina into γ-Al2O3. The OMCA-supporting Pt catalysts exhibited excellent performances in one-pot transformation of cellulose into hexitols thanks to the unique surface properties of the nanocomposite.
