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
The deactivation-regeneration of catalyst PdCl2-CuCl2-KOAc/AC in the synthesis of dimethyl carbonate （DMC） by gas-phase oxidative carbonylation was studied on the basis of XPS characterization and activity evaluatio...The deactivation-regeneration of catalyst PdCl2-CuCl2-KOAc/AC in the synthesis of dimethyl carbonate （DMC） by gas-phase oxidative carbonylation was studied on the basis of XPS characterization and activity evaluation.The reason for the catalyst deactivation is the loss of chlorine.The activity and stability of the fresh catalyst pretreated with methanol solution of methyl chloroacetate increases greatly.If the deactivated catalyst is treated with methanol solution of methyl chloroacetate and in N2 stream successively, the catalytic activity can be restored effectively and the regeneration induction period can be shortened.The catalytic activity after regeneration tiwice can still be restored to 93% of the fresh catalyst.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The deactivation-regeneration of catalyst PdCl2-CuCl2-KOAc/AC in the synthesis of dimethyl carbonate （DMC） by gas-phase oxidative carbonylation was studied on the basis of XPS characterization and activity evaluation.The reason for the catalyst deactivation is the loss of chlorine.The activity and stability of the fresh catalyst pretreated with methanol solution of methyl chloroacetate increases greatly.If the deactivated catalyst is treated with methanol solution of methyl chloroacetate and in N2 stream successively, the catalytic activity can be restored effectively and the regeneration induction period can be shortened.The catalytic activity after regeneration tiwice can still be restored to 93% of the fresh catalyst.
