CO2-TPD was demonstrated an effective way to investigate the phase formation during pyrolysis for the preparation of composite oxides using metal-organic molecules as precursors.Based on the CO2-TPD results, it was f...CO2-TPD was demonstrated an effective way to investigate the phase formation during pyrolysis for the preparation of composite oxides using metal-organic molecules as precursors.Based on the CO2-TPD results, it was found that calcination condition had deep effect on the carbonate formation and the minimum firing temperature to acquire pure phase composite oxide.An optimized calcination schedule was then developed.展开更多
A series of Fe/MgO catalysts were prepared by impregnation method and characterized by XRD and CO2-TPD.Selective synthesis of acrylonitrile from acetonitrile and methanol was carried out in a conventional flow reactor...A series of Fe/MgO catalysts were prepared by impregnation method and characterized by XRD and CO2-TPD.Selective synthesis of acrylonitrile from acetonitrile and methanol was carried out in a conventional flow reactor system.The effects of Fe loading and reaction temperatures on the catalytic properties of Fe/MgO were studied.Experimental results show the catalytic properties was greatly improved by the addition of Fe to MgO.As Fe loading was 5%,it had the best catalytic property with conversion 22.6% of acetonitrile and with selectivity to acrylonitrile 81.9% at 400℃.Excess addition of Fe results in a decrease in activity and selectivity.CO2-TPD showed that stronger and less base sites on the surface of catalysts were both unfavorable for the reaction.展开更多
A series of Mg Zn Al hydrotalcites like with different Mg/Zn molar ratios are synthesized by co precipitation method and characterized by XRD. The reactions of dehydrogenation or dehydration of isopropanol are carried...A series of Mg Zn Al hydrotalcites like with different Mg/Zn molar ratios are synthesized by co precipitation method and characterized by XRD. The reactions of dehydrogenation or dehydration of isopropanol are carried out using the Mg Zn Al mixed oxides obtained from calcination of Mg Zn Al hydrotalcites like. All of the Mg Zn Al mixed oxides show high catalytic activity on isopropanol dehydrogenation reaction. The acetone selectivity achieves more than 95%. The relation between catalytic activity and basicity of the catalysts is discussed by CO2 TPD technique.展开更多
文摘CO2-TPD was demonstrated an effective way to investigate the phase formation during pyrolysis for the preparation of composite oxides using metal-organic molecules as precursors.Based on the CO2-TPD results, it was found that calcination condition had deep effect on the carbonate formation and the minimum firing temperature to acquire pure phase composite oxide.An optimized calcination schedule was then developed.
文摘A series of Fe/MgO catalysts were prepared by impregnation method and characterized by XRD and CO2-TPD.Selective synthesis of acrylonitrile from acetonitrile and methanol was carried out in a conventional flow reactor system.The effects of Fe loading and reaction temperatures on the catalytic properties of Fe/MgO were studied.Experimental results show the catalytic properties was greatly improved by the addition of Fe to MgO.As Fe loading was 5%,it had the best catalytic property with conversion 22.6% of acetonitrile and with selectivity to acrylonitrile 81.9% at 400℃.Excess addition of Fe results in a decrease in activity and selectivity.CO2-TPD showed that stronger and less base sites on the surface of catalysts were both unfavorable for the reaction.
文摘A series of Mg Zn Al hydrotalcites like with different Mg/Zn molar ratios are synthesized by co precipitation method and characterized by XRD. The reactions of dehydrogenation or dehydration of isopropanol are carried out using the Mg Zn Al mixed oxides obtained from calcination of Mg Zn Al hydrotalcites like. All of the Mg Zn Al mixed oxides show high catalytic activity on isopropanol dehydrogenation reaction. The acetone selectivity achieves more than 95%. The relation between catalytic activity and basicity of the catalysts is discussed by CO2 TPD technique.
