Transesterification between methanol and propylene carbonate is investigated over transition metal oxide ZnO, CdO catalysts The effects of reaction conditions, the supports and promoter on the catalytic activity are a...Transesterification between methanol and propylene carbonate is investigated over transition metal oxide ZnO, CdO catalysts The effects of reaction conditions, the supports and promoter on the catalytic activity are also discussed It is indicated that the catalytic activity is closely related to the surface basicity of the catalysts The yield of DMC can be improved with the surface area and amount of basicity increasing Meanwhile, the addition of promoter is preferential for the DMC yield enhancing It is found that NaX CdO K 2CO 3 catalyst shows the highest activity towards the transesterification with PC conversion and DMC yield being 35 3% and 29 0%, respectively The optimum reaction conditions for NaX CdO K 2CO 3 catalyst are: temperature 393?K～413?K, time 3?展开更多
合成了系列漆酚 Lewis酸聚合物(简写为UR M,M∶Fe、Al金属离子)固体催化剂,并利用红外光谱分析进行了表征,通过实验筛选出了能催化合成醋酸正丁酯的最佳聚合物催化剂—"UR Fe Al",研究了UR Fe Al催化酯化反应的最佳条件和催...合成了系列漆酚 Lewis酸聚合物(简写为UR M,M∶Fe、Al金属离子)固体催化剂,并利用红外光谱分析进行了表征,通过实验筛选出了能催化合成醋酸正丁酯的最佳聚合物催化剂—"UR Fe Al",研究了UR Fe Al催化酯化反应的最佳条件和催化剂的重复使用性。结果表明:该催化剂催化活性高,重复使用性好,再生处理容易。展开更多
Highly active and stable nickel catalyst for dehydrogenation of methane and hydrogenation of benzene is prepared from a precursor with hydrotalcite-like anionic clam structure by coprecipitation. The nickel particles ...Highly active and stable nickel catalyst for dehydrogenation of methane and hydrogenation of benzene is prepared from a precursor with hydrotalcite-like anionic clam structure by coprecipitation. The nickel particles have a narrow size distribution in several nanometers, and have a strong interaction with other components such as Al2O3. This catalyst is highly sensitive to further modification by doping and to reaction condition. On a modified catalyst, benzene hydrogenation to cyclohexane proceeds to complete at 373 K. While on another catalyst, different structured nanocarbons are obtained at moderate temperatures. It is found that the thioresistance of the nickel catalyst in hydrogenation can be improved by doping.展开更多
The mechanics of porous catalyst paricles has been discussed and outlined. Concept of brittle fracture, statistical model of single-particle strength, and bulk crushing strength model were introduced. It is elucidated...The mechanics of porous catalyst paricles has been discussed and outlined. Concept of brittle fracture, statistical model of single-particle strength, and bulk crushing strength model were introduced. It is elucidated that the objective of catalyst mechanics research is to establish mechanical reliability model of converters using solid catalysts.展开更多
文摘Transesterification between methanol and propylene carbonate is investigated over transition metal oxide ZnO, CdO catalysts The effects of reaction conditions, the supports and promoter on the catalytic activity are also discussed It is indicated that the catalytic activity is closely related to the surface basicity of the catalysts The yield of DMC can be improved with the surface area and amount of basicity increasing Meanwhile, the addition of promoter is preferential for the DMC yield enhancing It is found that NaX CdO K 2CO 3 catalyst shows the highest activity towards the transesterification with PC conversion and DMC yield being 35 3% and 29 0%, respectively The optimum reaction conditions for NaX CdO K 2CO 3 catalyst are: temperature 393?K～413?K, time 3?
文摘合成了系列漆酚 Lewis酸聚合物(简写为UR M,M∶Fe、Al金属离子)固体催化剂,并利用红外光谱分析进行了表征,通过实验筛选出了能催化合成醋酸正丁酯的最佳聚合物催化剂—"UR Fe Al",研究了UR Fe Al催化酯化反应的最佳条件和催化剂的重复使用性。结果表明:该催化剂催化活性高,重复使用性好,再生处理容易。
基金Supported by the National Natural Science Foundation of China(No. 29792070-9, 29876032).
文摘Highly active and stable nickel catalyst for dehydrogenation of methane and hydrogenation of benzene is prepared from a precursor with hydrotalcite-like anionic clam structure by coprecipitation. The nickel particles have a narrow size distribution in several nanometers, and have a strong interaction with other components such as Al2O3. This catalyst is highly sensitive to further modification by doping and to reaction condition. On a modified catalyst, benzene hydrogenation to cyclohexane proceeds to complete at 373 K. While on another catalyst, different structured nanocarbons are obtained at moderate temperatures. It is found that the thioresistance of the nickel catalyst in hydrogenation can be improved by doping.
文摘The mechanics of porous catalyst paricles has been discussed and outlined. Concept of brittle fracture, statistical model of single-particle strength, and bulk crushing strength model were introduced. It is elucidated that the objective of catalyst mechanics research is to establish mechanical reliability model of converters using solid catalysts.
