质子交换膜恒电位式氢气传感器

A proton exchange membrane constant potential amperometry hydrogen sensor

利用质子交换膜为电解质 ,碳纸和铂黑分别为电极的扩散层和催化层 ,制作了恒电位式氢气传感器 ;确定的最佳施加电位是 0 .15V ;在氢气浓度为 0 .2 %内 ,氢气氧化电流与氢气浓度成正比 ;通过在工作电极前面加设聚乙烯膜 ,增大氢气扩散阻力 ,可以将氢气氧化电流与氢气浓度之间的线性关系提高到氢气浓度为 1.5% .

An electrochemical hydrogen sensor,comprised of three electrodes (working,counter,and reference)and a proton exchange membrane was made and studied.The electrodes were made of platinum and carbon paper,while the electrolyte is Nafion 117.The response was studied with constant potential amperometry.The highest H 2 oxidation current was observed at 0.15 V vs.reference electrode.At H 2 concentration below 0.15% ,there is a linear relation between H 2 concentration and H 2 oxidation current.Increasing resistance of H 2 diffusion with adding a polyethylene membrane before the working electrode,the linear relation between H 2 concentration and H 2 oxidation current can be kept until a high H 2 concentration(1.5%).