Polystyrene-supported hydroquinone （PS-HQ） is presented as an in situ polymeric cocatalyst to replace polystyrenesupported benzoquinone （PS-BQ） in the PdCl2-catalyzed acetalization of methyl acrylate with methanol...Polystyrene-supported hydroquinone （PS-HQ） is presented as an in situ polymeric cocatalyst to replace polystyrenesupported benzoquinone （PS-BQ） in the PdCl2-catalyzed acetalization of methyl acrylate with methanol in supercritical carbon dioxide （scCO2） under oxygen atmosphere. Due to deletion of H2O2 oxidation step, PS-HQ is more convenient and relatively inexpensive.展开更多
The catalysts supported on LiA1508 （spinel） for vapor phase synthesis of dimethyl carbonate （DMC） from methyl nitrite （MN） have been studied. Their catalytic activities on supports prepared by different methods ...The catalysts supported on LiA1508 （spinel） for vapor phase synthesis of dimethyl carbonate （DMC） from methyl nitrite （MN） have been studied. Their catalytic activities on supports prepared by different methods were evaluated in a continuous reactor. The samples were characterized by powder X-ray diffraction, N2 adsorption-desorption isotherms, fourier transform infrared spectroscopy and temperature-programmed reduction of H2. Li/A1 molar ratio and calcination temperature greatly influence the structure of crystalline phase of Li-AI-O oxides. Desirable LiAIsO8 （spinel） was formed at 800℃, while LiA1508 （primitive cube） formed at 900℃ is undesirable for the reaction. A high Li/A1 molar ratio, which was related with LiA102, also slowed the reaction rate. The electron transfer ability and the interaction with active component are the important properties of the spinel-based supports. The CuC12-PdC12/LiAIsO8 （spinel） with better electron transfer ability and low Pd2＋ reduction temperature exhibited a better catalytic ability.展开更多
文摘Polystyrene-supported hydroquinone （PS-HQ） is presented as an in situ polymeric cocatalyst to replace polystyrenesupported benzoquinone （PS-BQ） in the PdCl2-catalyzed acetalization of methyl acrylate with methanol in supercritical carbon dioxide （scCO2） under oxygen atmosphere. Due to deletion of H2O2 oxidation step, PS-HQ is more convenient and relatively inexpensive.
文摘The catalysts supported on LiA1508 （spinel） for vapor phase synthesis of dimethyl carbonate （DMC） from methyl nitrite （MN） have been studied. Their catalytic activities on supports prepared by different methods were evaluated in a continuous reactor. The samples were characterized by powder X-ray diffraction, N2 adsorption-desorption isotherms, fourier transform infrared spectroscopy and temperature-programmed reduction of H2. Li/A1 molar ratio and calcination temperature greatly influence the structure of crystalline phase of Li-AI-O oxides. Desirable LiAIsO8 （spinel） was formed at 800℃, while LiA1508 （primitive cube） formed at 900℃ is undesirable for the reaction. A high Li/A1 molar ratio, which was related with LiA102, also slowed the reaction rate. The electron transfer ability and the interaction with active component are the important properties of the spinel-based supports. The CuC12-PdC12/LiAIsO8 （spinel） with better electron transfer ability and low Pd2＋ reduction temperature exhibited a better catalytic ability.
