摘要
采用还原法制备了甲醇电氧化催化剂 ,运用循环伏安法测定了不同温度下催化剂的活性和稳定性。利用XRD技术分析了催化剂的晶体结构 ,制作了DMFC单电池 ,测定催化剂电化学性能。结果表明 :随着温度升高 ,甲醇电氧化峰值电流增大 ,峰值电位正移。在 0 .1mol·L- 1 CH3OH/ 0 .1mol·L- 1 H2 SO4电解液中 ,玻碳电极上所涂布的Pt催化剂量为 0 .2mg/cm2 时 ,80℃时的甲醇电氧化峰值电流达到 132mA/cm2 ,而峰值电位相对于Hg/Hg2 SO4电极 (MSE)仅为+0 .66V ,经多次循环扫描达到稳态峰值电流后 ,峰值电位不产生正移。XRD分析表明 ,催化剂中的铂以Pt( 111)晶态存在。采用液体进样 ,甲醇浓度为 2 .5mol·L- 1 ,常压、工作温度为 80℃时 ,DMFC单电池开路电压为 0 .58V ,输出电压为 0 .4V时 ,单电池输出电流达 16mA/cm2 。
The electrocatalyst for methanol electro-oxidation was prepared by the reduction method.Cyclic voltammetry was carried out to study electrochemical performance of electrocatalyst at different operating temperature.The crystalline structure of the electrocatalyst was analyzed by XRD.The results show that with the increasing of the operating temperature,the designated constant current for the complete oxidation of methanol increased as well as the designated constant potential for the complete oxidation.When the quantity of catalyst on glass-carbon electrode reaches 0.2 mg Pt/cm 2,the designated constant current of the prepared catalyst achieves 132 mA/cm 2 in 0.1 mol·L -1 CH 3OH/0.1 mol·L -1 H 2SO 4 at 80 ℃,and the designated constant potential is only 0.66 V vs.Hg/Hg 2SO 4 electrode(MES).There is no increasing of the designated constant potential for the complete oxidation when the designated constant current is stable after many cycles.According to the characterization of XRD,the electrocatalyst present a single metallic phase(mainly Pt(111)).When the concentration of methanol is 2.5 mol·L -1,the OCV of DMFC single cell is 0.58 V with the operating temperature of 80 ℃ at atmoshpheric pressure,and the output current of single cell reaches 16 mA/cm 2 with the output voltage of 0.4 V.
出处
《电源技术》
EI
CAS
CSCD
北大核心
2000年第4期218-220,共3页
Chinese Journal of Power Sources
基金
广东省自然科学基金资助项目! ( 980 52 0 )
