银/二氧化锰复合催化剂的制备及其对氧还原的电化学活性  

Synthesis and Electrochemical Activity of Silver and Manganese Dioxide Composites for Oxygen Reduction Reaction

作　　者：阳铮 易清风[1] 向柏霖[2] Yang Zheng;Yi Qingfeng;Xiang Bolin(School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;School of Chemistry and Chemical Engineering, Huaihua University, Huaihua 418000, China)

机构地区：[1]湖南科技大学化学化工学院,湖南湘潭411201 [2]怀化学院化学化工学院,湖南怀化418000

出　　处：《湖南科技大学学报（自然科学版）》2018年第1期71-77,共7页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(21376070);湖南省自然科学基金资助项目(14JJ2096)

摘　　要：通过化学还原法,在多壁碳纳米管（MWCNT）负载的二氧化锰纳米颗粒表面上进一步沉积银纳米颗粒,制备银/二氧化锰电极材料（Ag/MnO2/MWCNT）.利用循环伏安（CV）和线性扫描技术（LSV）,测试了这些催化剂对碱性溶液中氧还原反应（ORR）的电化学活性.结果表明,MnO2为5%（wt%）与10%的催化剂对ORR均表现出强的电活性,它们的ORR起始电位约为0.02 V（vs. Hg/Hg O）.在Ag/5%MnO2/MWCNT电极上,ORR的极限扩散电流密度是2.86×10-（-3）A/cm-2（1 200 r/min）,高于Ag/MWCNT.Levich方程分析表明,在Ag/5%MnO2/MWCNT催化剂上,ORR电子转移数明显大于Ag/MWCNT,说明在Ag/5%MnO2/MWCNT上氧气能更彻底地还原.结果表明,适量MnO2的加入能明显改善Ag/MWCNT对ORR的电活性.Silver/manganese dioxide/multi-walled carbon nanotubes（Ag/MnO2/MWCNT） composites with different MnO2 loadings were prepared by chemical reduction method. Cyclic voltammetry and linear sweep voltammetry were used to investigate the electroactivity of the samples for oxygen reduction reaction（ORR） in the alkaline solution. The results show that both Ag/5% MnO2/MWCNT and Ag/10% MnO2/MWCNT exhibit a high electrocatalytic activity,with the onset potential of ca. 0. 02 V（vs. Hg/Hg O） and the ORR limiting current density of 5% Ag/MnO2/MWCNT is 2. 86 x 10-（-3）A/cm-2（1 200 r/min）,higher than that of Ag/MWCNT. Levich analysis is shown that Ag/5% MnO2/MWCNT possesses a much greater electron-transfer number for ORR than Ag/MWCNT,which indicates the more complete reduction of oxygen on the Ag/5%MnO2/MWCNT.

关 键 词：纳米银 二氧化锰 氧还原 燃料电池 

分 类 号：O646.7[理学—物理化学]