Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at tempe...Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at temperatures between 450℃ and 900℃ in N2 artmosphere. Then, in a successive activation stage, the product carbonized at 600℃ was activated in steam at 450 - 900℃ for 30 min, and at 600℃for 5- 30 min. The other carbonization products were activated at 600 and 900℃ for 30 min respectively. The products activated at 900℃ were then activated at 450℃ for 30 min again. The starting material, carbonized products and all activation products were examined by FT-IR spectroscopy and some products were examined by X-ray photoelectron spectroscope (XPS). And the yields of the carbonized and activated products were calculated. By analysing these spectra, the amount of oxygen-containing functional groups of the activated products attained under various activation time, various activation temperature and various previous carbonization temperature was determined.展开更多
The adsorption of acetonitrile and its co-adsorption with CO on fresh Mo<sub>2</sub>C/Al<sub>2</sub>O<sub>3</sub> catalyst have been studied by insitu FT-IR spectroscopy.Linearly ad...The adsorption of acetonitrile and its co-adsorption with CO on fresh Mo<sub>2</sub>C/Al<sub>2</sub>O<sub>3</sub> catalyst have been studied by insitu FT-IR spectroscopy.Linearly adsorbed CH<sub>3</sub>CN and CH<sub>3</sub>CH<sub>2</sub>NH<sub>2</sub> were formed after CH<sub>3</sub>CN adsorption on the Mo<sub>2</sub>C/ Al<sub>2</sub>O<sub>3</sub> catalyst.The appearance of a strong band at 1578 cm<sup>-1</sup> indicates that CH<sub>3</sub>CN was reactive with hydrogen on the Mo<sub>2</sub>C/Al<sub>2</sub>O<sub>3</sub> catalyst.展开更多
The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on Ce...The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on CeO2 and Pr6O11 under CO atmosphere at 200℃ . and the reaction becomcs more prevailing at higher temperatures especially for partially reduced samples. The surface formate species are produced via the reaction of CO with surface hydroxyls which was confirmed by the reaction of CO with D2-treated CeO2 and Pr6O11. The Surface formate can be oxidized to carbonate at temperatures exceeding 300 ℃, and the surface hydroxyls could be recovered as the formate species decompose or are oxidized to carbonate species. The roles played by the surface hydroxyls and surface active sites in the CO oxidation are discussed.展开更多
Polyaniline-fly ash (PANI-FA) composites were prepared by oxidative polymerization of aniline with fly ash in presence of ammonium persulphate (APS). The PANI-FA composites were prepared with different concentrations ...Polyaniline-fly ash (PANI-FA) composites were prepared by oxidative polymerization of aniline with fly ash in presence of ammonium persulphate (APS). The PANI-FA composites were prepared with different concentrations of fly ash to aniline ratio. The composites, so prepared, were characterized by UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The thermal stability was studied by TGA and total weight loss of PANI, FA and PANI-FA composites having FA composition of 0.02%, 0.1%, 0.5% and 1.0% were found to be 82%, 39.%, 67% 65%, 62% and 61%, respectively. The UV-vis spectroscopy of the PANI-FA polymeric composite shows absorption maxima at 315 and 350 nm (due to π-π* transition of the benzenoid rings), and 578-712 nm (due to charge transfer excitations of the quinoid structure), which are characteristic of emeraldine base. FTIR spectra of the PANI-FA composite is similar to that of pure polyaniline (PANI) but with the bands for C=N, C=C and C-N shifted to lower wave numbers, i.e., 1585, 1494, 1327 and 1113 cm?1 due to strong interaction of Fe2O3 and PANI matrix. SEM shows the complexation of metal oxide with emaraldine base of PANI, significantly changing the aggregate state of polymeric molecular chain.展开更多
文摘Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at temperatures between 450℃ and 900℃ in N2 artmosphere. Then, in a successive activation stage, the product carbonized at 600℃ was activated in steam at 450 - 900℃ for 30 min, and at 600℃for 5- 30 min. The other carbonization products were activated at 600 and 900℃ for 30 min respectively. The products activated at 900℃ were then activated at 450℃ for 30 min again. The starting material, carbonized products and all activation products were examined by FT-IR spectroscopy and some products were examined by X-ray photoelectron spectroscope (XPS). And the yields of the carbonized and activated products were calculated. By analysing these spectra, the amount of oxygen-containing functional groups of the activated products attained under various activation time, various activation temperature and various previous carbonization temperature was determined.
文摘The adsorption of acetonitrile and its co-adsorption with CO on fresh Mo<sub>2</sub>C/Al<sub>2</sub>O<sub>3</sub> catalyst have been studied by insitu FT-IR spectroscopy.Linearly adsorbed CH<sub>3</sub>CN and CH<sub>3</sub>CH<sub>2</sub>NH<sub>2</sub> were formed after CH<sub>3</sub>CN adsorption on the Mo<sub>2</sub>C/ Al<sub>2</sub>O<sub>3</sub> catalyst.The appearance of a strong band at 1578 cm<sup>-1</sup> indicates that CH<sub>3</sub>CN was reactive with hydrogen on the Mo<sub>2</sub>C/Al<sub>2</sub>O<sub>3</sub> catalyst.
文摘The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on CeO2 and Pr6O11 under CO atmosphere at 200℃ . and the reaction becomcs more prevailing at higher temperatures especially for partially reduced samples. The surface formate species are produced via the reaction of CO with surface hydroxyls which was confirmed by the reaction of CO with D2-treated CeO2 and Pr6O11. The Surface formate can be oxidized to carbonate at temperatures exceeding 300 ℃, and the surface hydroxyls could be recovered as the formate species decompose or are oxidized to carbonate species. The roles played by the surface hydroxyls and surface active sites in the CO oxidation are discussed.
文摘Polyaniline-fly ash (PANI-FA) composites were prepared by oxidative polymerization of aniline with fly ash in presence of ammonium persulphate (APS). The PANI-FA composites were prepared with different concentrations of fly ash to aniline ratio. The composites, so prepared, were characterized by UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The thermal stability was studied by TGA and total weight loss of PANI, FA and PANI-FA composites having FA composition of 0.02%, 0.1%, 0.5% and 1.0% were found to be 82%, 39.%, 67% 65%, 62% and 61%, respectively. The UV-vis spectroscopy of the PANI-FA polymeric composite shows absorption maxima at 315 and 350 nm (due to π-π* transition of the benzenoid rings), and 578-712 nm (due to charge transfer excitations of the quinoid structure), which are characteristic of emeraldine base. FTIR spectra of the PANI-FA composite is similar to that of pure polyaniline (PANI) but with the bands for C=N, C=C and C-N shifted to lower wave numbers, i.e., 1585, 1494, 1327 and 1113 cm?1 due to strong interaction of Fe2O3 and PANI matrix. SEM shows the complexation of metal oxide with emaraldine base of PANI, significantly changing the aggregate state of polymeric molecular chain.
