Silica was used, as a catalyst carrier, to load cerous sulfate for catalyzing the synthesis of n-butyl acetate. The main purpose of this research was to explore the feasibility of silica in improving the decentrality ...Silica was used, as a catalyst carrier, to load cerous sulfate for catalyzing the synthesis of n-butyl acetate. The main purpose of this research was to explore the feasibility of silica in improving the decentrality and activity of the catalyst. The effects of molar ratio of butyl alcohol to acetic acid, the cerous sulfate loadings and the reaction time on the conversion of acetic acid were studied by single factor experiment method and orthogonal experiment method respectively. The refractive index (n20D) and molecular structure of the prepared n-butyl acetate were measured by Abbe Raefractometer and Fourier Transform Infrared spectroscope, respectively. The comparisons of the silica loaded and unloaded catalysts for catalyzing the synthesis of n-butyl acetate were made. The results showed that the suitable conditions for synthesizing n-butyl acetate were: molar ratio of butyl alcohol to acetic acid of 1.4∶1, use level of loaded cerous sulfate of 0.30 g and reaction time of 50 min, respectively. The maximum conversion of acetic acid for the silica loaded catalyst reached 98.62% which was 12.32% and 16.43% higher than those for the unloaded catalysts reported in literatures, but the use level of cerous sulfate for the former was much less than those for the latters under similar optimal technical conditions. The silica was proved to be a good catalyst carrier for enhancing decentrality and activity of the catalyst and increasing the conversion of acetic acid. The repentance of the silica loaded cerous sulfate was also investigated in the experiment.展开更多
The main purpose of this article is to use rare earths to modify the electroless plating process for metallizing the surface of quartz optical fibers (silicon fibers). The effects of Yb, Ce and La on the deposition ra...The main purpose of this article is to use rare earths to modify the electroless plating process for metallizing the surface of quartz optical fibers (silicon fibers). The effects of Yb, Ce and La on the deposition rate of Ni-P, the stability of plating solution and the surface structure of Ni-P film were investigated and their mechanisms were discussed. The surface morphonogies and compositions of the Ni-P films were characterized and analyzed by SEM, MSM, XRD and ESM, respectively. The experimental results showed that Ce(SO4)2 with concentration of 40 mg·L-1 was proved to be the best choice for increasing the deposition rate, enhancing the stability of plating solution and improving the quality of deposited Ni-P film compared with the other two kind of rare earths. The detections of ESM exhibited no effect of Ce on film compositions and no Ce deposition being found in the film prepared by electroless plating with adding Ce because of its much more negative deposition potential than those of the reducing agents used in the experiment. The addition of Ce resulted in a transmission of the film surface structure from crystal structure into a microcrystallitic structure. The Ni-P film with thickness of about 45 μm prepared using electroless plating by adding Ce(SO4)2 with concentration of 40 mg·L-1 had good quality, which will be satisfactorily for the next Ni deposition by electroplating.展开更多
基金Jiangxi Programs for Science and Technology Development (2005)
文摘Silica was used, as a catalyst carrier, to load cerous sulfate for catalyzing the synthesis of n-butyl acetate. The main purpose of this research was to explore the feasibility of silica in improving the decentrality and activity of the catalyst. The effects of molar ratio of butyl alcohol to acetic acid, the cerous sulfate loadings and the reaction time on the conversion of acetic acid were studied by single factor experiment method and orthogonal experiment method respectively. The refractive index (n20D) and molecular structure of the prepared n-butyl acetate were measured by Abbe Raefractometer and Fourier Transform Infrared spectroscope, respectively. The comparisons of the silica loaded and unloaded catalysts for catalyzing the synthesis of n-butyl acetate were made. The results showed that the suitable conditions for synthesizing n-butyl acetate were: molar ratio of butyl alcohol to acetic acid of 1.4∶1, use level of loaded cerous sulfate of 0.30 g and reaction time of 50 min, respectively. The maximum conversion of acetic acid for the silica loaded catalyst reached 98.62% which was 12.32% and 16.43% higher than those for the unloaded catalysts reported in literatures, but the use level of cerous sulfate for the former was much less than those for the latters under similar optimal technical conditions. The silica was proved to be a good catalyst carrier for enhancing decentrality and activity of the catalyst and increasing the conversion of acetic acid. The repentance of the silica loaded cerous sulfate was also investigated in the experiment.
文摘The main purpose of this article is to use rare earths to modify the electroless plating process for metallizing the surface of quartz optical fibers (silicon fibers). The effects of Yb, Ce and La on the deposition rate of Ni-P, the stability of plating solution and the surface structure of Ni-P film were investigated and their mechanisms were discussed. The surface morphonogies and compositions of the Ni-P films were characterized and analyzed by SEM, MSM, XRD and ESM, respectively. The experimental results showed that Ce(SO4)2 with concentration of 40 mg·L-1 was proved to be the best choice for increasing the deposition rate, enhancing the stability of plating solution and improving the quality of deposited Ni-P film compared with the other two kind of rare earths. The detections of ESM exhibited no effect of Ce on film compositions and no Ce deposition being found in the film prepared by electroless plating with adding Ce because of its much more negative deposition potential than those of the reducing agents used in the experiment. The addition of Ce resulted in a transmission of the film surface structure from crystal structure into a microcrystallitic structure. The Ni-P film with thickness of about 45 μm prepared using electroless plating by adding Ce(SO4)2 with concentration of 40 mg·L-1 had good quality, which will be satisfactorily for the next Ni deposition by electroplating.
