The dehydrogenation reaction of ethane over Cr/CeO2 catalysts in presence of CO2 was studied with fixed-bed micro-reactor. The Cr/CeO2 catalysts of different Cr loading have been synthesized using impregnation techniq...The dehydrogenation reaction of ethane over Cr/CeO2 catalysts in presence of CO2 was studied with fixed-bed micro-reactor. The Cr/CeO2 catalysts of different Cr loading have been synthesized using impregnation techniques. The Cr/CeO2 system has already been found to be active and selective in the reaction at around 740 ℃. The function of carbon dioxide is to remove coke and hydrogen to accelerate dehydrogenation of ethane. The results of catalysts characterizations indicated that Cr3+ and Cr6+ occurred on the surface of the catalysts. The 1.2 mmol Cr/100m2 CeO2 catalyst sample with a monolayer dispersion of Cr on CeO2 support showed a stronger surface acidity and a maximum yield of ethylene of about 35.5% at 36.6% conversion of ethane.展开更多
The dehydrogenation of cyclohexane was studied in a packed bed membrane reactor （MR） with massfraction 0.5% Pt/A1203 catalyst granules,and also in a traditional packed bed reactor for comparision.Equilibrium shiftin...The dehydrogenation of cyclohexane was studied in a packed bed membrane reactor （MR） with massfraction 0.5% Pt/A1203 catalyst granules,and also in a traditional packed bed reactor for comparision.Equilibrium shifting was obtained at different reaction conditions such as temperature,reactant concentration,inlet gas flow rate and sweep gas flow rate.The conversion increased with sweep gas rate,but a high inlet gas rate resulted in low conversion in the MR.UP to 3.1 equilibrium conversion,which is 20.6%,was obtained in the MR at 200℃.展开更多
Effects of various factors on the reaction conversion were calculated by theapplication of self-progranund software and thermodyntalc data; Activities and selectiv-ities of various ZnO/silica-based catalysts were comp...Effects of various factors on the reaction conversion were calculated by theapplication of self-progranund software and thermodyntalc data; Activities and selectiv-ities of various ZnO/silica-based catalysts were compared; Reaction mechhasm based onthermodyntalc equilibrium and products distribution of the reactions was also展开更多
The aniline solution containing nicotinamide adenine dinucleotide(NAD＋ )was electrolyzed. Polyaniline film with NAD＋ formed on the platinum thin plate. The thickness of the film was controlled by the charge consumed...The aniline solution containing nicotinamide adenine dinucleotide(NAD＋ )was electrolyzed. Polyaniline film with NAD＋ formed on the platinum thin plate. The thickness of the film was controlled by the charge consumed in the electrolysis, which was 0.006 C in this case. This electrode, used as an anode, was immersed in the solution containing aniline.A second film formed on this electrode during the electrolysis. The charge passed during the second electrolysis was 0.016 C. Alcohol dehydrogenase(ADH) was immobilized on the polyaniline film based on the isoelectric point of ADH and the doping principle of conducting polymers. The enzyme electrode has a good bioelectrochemical response to ethanol in the absence of a homogeneous mediator. The optimum pH, apparent Michaelis- Menten constant and optimum temperature of ADH immobilized in polyaniline film are 7.83, 7.5 mmol· dm－ 3, and 30.6 ℃ , respectively.The activation energy of the enzyme- catalyzed reaction is 33.5 kJ· mol－ 1. The response current of the enzyme electrode increases linearly with increasing concentration of ethanol below 2.4 mmol· dm－ 3.This enzyme electrode can be used to determine the concentration of ethanol.展开更多
文摘The dehydrogenation reaction of ethane over Cr/CeO2 catalysts in presence of CO2 was studied with fixed-bed micro-reactor. The Cr/CeO2 catalysts of different Cr loading have been synthesized using impregnation techniques. The Cr/CeO2 system has already been found to be active and selective in the reaction at around 740 ℃. The function of carbon dioxide is to remove coke and hydrogen to accelerate dehydrogenation of ethane. The results of catalysts characterizations indicated that Cr3+ and Cr6+ occurred on the surface of the catalysts. The 1.2 mmol Cr/100m2 CeO2 catalyst sample with a monolayer dispersion of Cr on CeO2 support showed a stronger surface acidity and a maximum yield of ethylene of about 35.5% at 36.6% conversion of ethane.
文摘The dehydrogenation of cyclohexane was studied in a packed bed membrane reactor （MR） with massfraction 0.5% Pt/A1203 catalyst granules,and also in a traditional packed bed reactor for comparision.Equilibrium shifting was obtained at different reaction conditions such as temperature,reactant concentration,inlet gas flow rate and sweep gas flow rate.The conversion increased with sweep gas rate,but a high inlet gas rate resulted in low conversion in the MR.UP to 3.1 equilibrium conversion,which is 20.6%,was obtained in the MR at 200℃.
文摘Effects of various factors on the reaction conversion were calculated by theapplication of self-progranund software and thermodyntalc data; Activities and selectiv-ities of various ZnO/silica-based catalysts were compared; Reaction mechhasm based onthermodyntalc equilibrium and products distribution of the reactions was also
文摘The aniline solution containing nicotinamide adenine dinucleotide(NAD＋ )was electrolyzed. Polyaniline film with NAD＋ formed on the platinum thin plate. The thickness of the film was controlled by the charge consumed in the electrolysis, which was 0.006 C in this case. This electrode, used as an anode, was immersed in the solution containing aniline.A second film formed on this electrode during the electrolysis. The charge passed during the second electrolysis was 0.016 C. Alcohol dehydrogenase(ADH) was immobilized on the polyaniline film based on the isoelectric point of ADH and the doping principle of conducting polymers. The enzyme electrode has a good bioelectrochemical response to ethanol in the absence of a homogeneous mediator. The optimum pH, apparent Michaelis- Menten constant and optimum temperature of ADH immobilized in polyaniline film are 7.83, 7.5 mmol· dm－ 3, and 30.6 ℃ , respectively.The activation energy of the enzyme- catalyzed reaction is 33.5 kJ· mol－ 1. The response current of the enzyme electrode increases linearly with increasing concentration of ethanol below 2.4 mmol· dm－ 3.This enzyme electrode can be used to determine the concentration of ethanol.
