Highly ordered mesoporous carbon-alumina nanocomposites （OMCA） have been synthesized for the first time by a multi-component co-assembly method followed by pyrolysis at high temperatures. In this synthesis, resol ph...Highly ordered mesoporous carbon-alumina nanocomposites （OMCA） have been synthesized for the first time by a multi-component co-assembly method followed by pyrolysis at high temperatures. In this synthesis, resol phenol-formaldehyde resin （PF resin） and alumina sol were respectively used as the carbon and alumina precursors and triblock copolymer Pluronic F127 as the template. N2-adsorption measurements, 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 was retained. Further increasing the alumina content to 53 wt.% resulted in wormhole-like structures, although the pore size distribution was still narrow. The nanocomposite walls are composed of continuous carbon and amorphous alumina, which allows the ordered mesostructure to be well preserved even after the removal of alumina by HF etching or the removal of carbon by calcination in air. The OMCA nanocomposites exhibited good thermostability below 1000℃; at higher temperatures the ordered mesostructure partially collapsed, associated with a phase transformation from amorphous alumina into γ-Al2O3. OMCA-supported Pt catalysts exhibited excellent performance in the one-pot transformation of cellulose into hexitols thanks to the unique surface properties of the nanocomposite.展开更多
Graphitized nanocarbon materials can be an ideal catalyst support for heterogeneous catalytic systems. Their unique physical and chemical properties, such as large surface area, high adsorption capacity, excellent the...Graphitized nanocarbon materials can be an ideal catalyst support for heterogeneous catalytic systems. Their unique physical and chemical properties, such as large surface area, high adsorption capacity, excellent thermal and mechanical stability, outstanding electronic properties, and tunable porosity, allow the anchoring and dispersion of the active metals. Therefore, currently they are used as the key support material in many catalytic processes. This review summarizes recent relevant applications in supported catalysts that use graphitized nanocarbon as supports for catalytic oxidation, hydrogenation, dehydrogenation, and C-C coupling reactions in liquid-phase and gas-solid phase-reaction systems. The latest developments in specific features derived from the morphology and characteristics of graphitized na- nocarbon-supported metal catalysts are highlighted, as well as the differences in the catalytic behavior of graphitized nano- carbon-supported metal catalysts versus other related cata- lysts. The scientific challenges and opportunities in this field are also discussed.展开更多
文摘Highly ordered mesoporous carbon-alumina nanocomposites （OMCA） have been synthesized for the first time by a multi-component co-assembly method followed by pyrolysis at high temperatures. In this synthesis, resol phenol-formaldehyde resin （PF resin） and alumina sol were respectively used as the carbon and alumina precursors and triblock copolymer Pluronic F127 as the template. N2-adsorption measurements, 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 was retained. Further increasing the alumina content to 53 wt.% resulted in wormhole-like structures, although the pore size distribution was still narrow. The nanocomposite walls are composed of continuous carbon and amorphous alumina, which allows the ordered mesostructure to be well preserved even after the removal of alumina by HF etching or the removal of carbon by calcination in air. The OMCA nanocomposites exhibited good thermostability below 1000℃; at higher temperatures the ordered mesostructure partially collapsed, associated with a phase transformation from amorphous alumina into γ-Al2O3. OMCA-supported Pt catalysts exhibited excellent performance in the one-pot transformation of cellulose into hexitols thanks to the unique surface properties of the nanocomposite.
基金supported by the Ministry of Science and Technology (2016YFA0204100)the National Natural Science Foundation of China (21573254 and 91545110)+1 种基金the Youth Innovation Promotion Association (CAS)the Sinopec China and Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09030103)
文摘Graphitized nanocarbon materials can be an ideal catalyst support for heterogeneous catalytic systems. Their unique physical and chemical properties, such as large surface area, high adsorption capacity, excellent thermal and mechanical stability, outstanding electronic properties, and tunable porosity, allow the anchoring and dispersion of the active metals. Therefore, currently they are used as the key support material in many catalytic processes. This review summarizes recent relevant applications in supported catalysts that use graphitized nanocarbon as supports for catalytic oxidation, hydrogenation, dehydrogenation, and C-C coupling reactions in liquid-phase and gas-solid phase-reaction systems. The latest developments in specific features derived from the morphology and characteristics of graphitized na- nocarbon-supported metal catalysts are highlighted, as well as the differences in the catalytic behavior of graphitized nano- carbon-supported metal catalysts versus other related cata- lysts. The scientific challenges and opportunities in this field are also discussed.
