摘要
采用半池考察了Pt/C催化剂在含不同浓度甲醇的0.5mol/L硫酸中的氧还原活性(ORR).研究发现,当甲醇浓度为0.1mol/L时,Pt/C催化剂的ORR活性最高,在催化层上热压商品NafionNRE-212膜后也出现同样趋势.线性扫描伏安曲线显示,压膜前后的Pt/C催化剂的ORR活性在含0.1mol/L甲醇的0.5mol/L硫酸中几乎没有变化.电化学阻抗谱结果表明,在该溶液中,Nafion膜的电阻比在其它电解液中低,这可能是导致Pt/C催化剂ORR活性提高的主要原因.有必要关注Nafion膜的这一异常性质并通过特殊设计后用于电池堆,以提高燃料电池性能.
The oxygen reduction reaction (ORR) activity of Pt/C catalysts was investigated in electrolytes of 0.5 mol/L H2SO4 containing varying concentrations of methanol in a half‐cell. It was found that the ORR activity was improved notably in an electrolyte of 0.5 mol/L H2SO4 containing 0.1 mol/L CH3 OH as compared with that in 0.5 mol/L H2SO4 , 0.5 mol/L H2SO4 containing 0.5 mol/L CH3OH, or 0.5 mol/L H2SO4 containing 1.0 mol/L CH3OH electrolytes. The same tendency for improved ORR activity was also apparent after commercial Nafion NRE‐212 membrane was hot‐pressed onto the catalyst layers. The linear sweep voltammetry results indicate that the ORR activities of the Pt/C catalyst were almost identical in the 0.5 mol/L H2SO4 + 0.1 mol/L CH3OH solution before and after coated with the Nafion membrane. Electrochemical impedance spectroscopy results demonstrated that the resistance of the Nafion membrane is smaller in the electrolyte of 0.5 mol/L H2SO4 + 0.1 mol/L CH3OH than in other electrolytes with oxygen gas feed. This exceptional property of the Nafion membrane is worth investigating and can be applied in fuel cell stacks to improve the system performance.
出处
《催化学报》
CSCD
北大核心
2013年第6期1105-1111,共7页
关键词
铂
炭
甲醇渗透
氧还原
燃料电池
Platinum
Carbon
Methanol crossover
Oxygen reduction
Fuel cell
