采用硝酸铜溶液和NaY分子筛溶液离子交换制备了CuY催化剂,通过加入氨水提高交换溶液的pH值以及高温焙烧活化,显著提高了该催化剂对甲醇氧化羰基化合成碳酸二甲酯的催化活性,与固相离子交换、沉积和浸渍法制备的催化剂相比,虽然铜的负载...采用硝酸铜溶液和NaY分子筛溶液离子交换制备了CuY催化剂,通过加入氨水提高交换溶液的pH值以及高温焙烧活化,显著提高了该催化剂对甲醇氧化羰基化合成碳酸二甲酯的催化活性,与固相离子交换、沉积和浸渍法制备的催化剂相比,虽然铜的负载量较低,但催化活性较高.通过元素分析、XRD、H2-TPR、XPS和Auger电子能谱(Auger electron spectroscopy,AES)等手段对CuY催化剂微观结构的表征结果表明,在Cu(NO3)2离子交换溶液中加入氨水,可促进Cu2+离子交换的进行,提高CuY催化剂的Cu交换量,并且交换的Cu2+主要位于分子筛的超笼中.在惰性气氛中焙烧活化CuY催化剂,Cu2+自还原为Cu+,氨促进了自还原过程的进行,显著提高了催化剂的活性.焙烧活化温度越高,越有利于超笼中Cu2+→Cu+的自还原过程,使超笼中Cu+的含量增加,CuY催化活性增加.进一步的研究结果表明,Y分子筛超笼中的Cu+是主要的催化活性中心.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
文摘采用硝酸铜溶液和NaY分子筛溶液离子交换制备了CuY催化剂,通过加入氨水提高交换溶液的pH值以及高温焙烧活化,显著提高了该催化剂对甲醇氧化羰基化合成碳酸二甲酯的催化活性,与固相离子交换、沉积和浸渍法制备的催化剂相比,虽然铜的负载量较低,但催化活性较高.通过元素分析、XRD、H2-TPR、XPS和Auger电子能谱(Auger electron spectroscopy,AES)等手段对CuY催化剂微观结构的表征结果表明,在Cu(NO3)2离子交换溶液中加入氨水,可促进Cu2+离子交换的进行,提高CuY催化剂的Cu交换量,并且交换的Cu2+主要位于分子筛的超笼中.在惰性气氛中焙烧活化CuY催化剂,Cu2+自还原为Cu+,氨促进了自还原过程的进行,显著提高了催化剂的活性.焙烧活化温度越高,越有利于超笼中Cu2+→Cu+的自还原过程,使超笼中Cu+的含量增加,CuY催化活性增加.进一步的研究结果表明,Y分子筛超笼中的Cu+是主要的催化活性中心.
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.
