摘要
采用Nafion膜作为电解质、β-PbO2颗粒作为阳极、碳载铂作为阴极,制备了固体聚合物电解质复合膜电极.利用SEM和XRD研究发现,膜电极运行220h后,阳极PbO2中约有6%左右的α-PbO2,阳极催化层颗粒之间变得疏松,PbO2颗粒的表面也出现了大量重结晶的纳米尺寸的PbO2颗粒,膜电极出现电流效率下降和槽压上升的趋势.阳极PbO2重结晶导致的催化层结构和形貌改变是这种趋势出现的主要原因;晶体中的Pb2+被氧化为Pb4+所致的晶体原有结构的破坏可能是膜电极性能下降的原因之一.膜电极在运行到180h后,槽压和电流效率趋于稳定,这可能是由于阳极催化层的结构已趋于稳定。
The solid polymer electrolyte composite membrane electrode was prepared by using Nation membrane, lead dioxide and carbon-supported platinum as the electrolyte, anodic and cathodic catalyst, respectively. Morphology and structure studies of the membrane electrode with scanning electron microscopy and X-ray diffraction showed that with ozone production for 220 h, there was about 6% α-PbO2 in the lead dioxide anode. Meanwhile, the bonding structure of anode became loose and there were a lot of re-crystallized nano-sized particles on the surface of anode. The current efficiency of ozone evolution on the electrode decreased, and its voltage increased with time. It was fotmd that the main reason for the degradations was change in morphology and structure of catalyst layer caused by recrystallization of lead dioxide, and the other reason was change in structure of lead dioxide induced by reduction of Pb^2＋ to Pb^4＋. With 180 h running of the electrode, the voltage and current efficiency of the electrode became steady, the reason might be the structure of anodic catalyst layer tending to remain stable.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2008年第2期404-408,共5页
The Chinese Journal of Process Engineering
基金
陕西省科技攻关基金资助项目(编号:2006K01-G30)
陕西省教育厅专项科研计划基金资助项目(编号:JK194)
关键词
臭氧
膜电极
二氧化铅
重结晶
ozone
membrane electrode
lead dioxide
re-crystallization
