moCNTs/PyPBI/Mela(Co)电催化剂的制备及性能研究  

Preparation and electrochemical activity of moCNTs/PyPBI/Mela(Co) electrocatalysts

作　　者：于书平[1] 梁新凯 朱红[1] 杨文胜[1] 韩克飞[1] 汪中明[1] YU ShuPing LIANG XinKai ZHU Hong YANG WenSheng HAN KeFei WANG ZhongMing(State Key Laboratory of Chemical Resource Engineering, Faculty of Science, Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学理学院化工资源有效利用国家重点实验室,北京100029

出　　处：《北京化工大学学报（自然科学版）》2016年第5期14-21,共8页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：中央高校基本科研业务费(YS1406);国家自然科学基金(21276021/21176023)

摘　　要：采用溶液共混和高温热解两步法,以聚苯并咪唑(PyPBI)和三聚氰胺(Mela)为复合氮源,中度氧化的碳纳米管(moCNTs)为碳源,醋酸钴为金属源,制备出一系列moCNTs/PyPBI/Mela(Co)催化剂,对其进行TEM、TGA、XRD、XPS表征和电化学活性测试,结果表明:当moCNTs/PyPBI(Co)前驱体与三聚氰胺的质量比为1∶2,热解温度为800℃时,催化剂的起始还原电位可达到0.87V(vs.RHE),接近于商业Pt20%/C催化剂。moCNTs/PyPBI/Mela(Co)催化剂催化性能的提高归因于其结构中的吡啶氮与钴结合形成Co-N活性位点,增加对O2的吸附能力,弱化了O—O键,促进氧分子的还原反应,促使ORR反应通过4e-途径进行。Using mildly oxidized carbon nanotubes（ mo CNTs） as the carbon source,and pyridyl-linked polybenzimidazole（ Py PBI） and melamine as a binary nitrogen source mo CNTs/Py PBI/Mela（ Co） electrocatalysts have been prepared by a two-step method involving solution blending and pyrolysis.The results showed that the electrocatalysts prepared using binary nitrogen sources had a higher electrocatalytic activity than the electrocatalysts prepared using single nitrogen sources.The electrocatalysts prepared at 800 ℃ had the highest electrocatalytic activity,with a maximum ORR onset potential of 0.87 V（ vs.RHE）,which is only 0.07 V lower than that of Pt 20%/C（ JM）.We conclude that the nitrogen sources are decomposed and N atoms enter into the carbon lattice to product more pyridinic nitrogen and form Co-N active sites during the pyrolysis process.Pyridinic N atoms at Co-N active sites can increase charge delocalization degree and enable the carbon around the pyridinic N atoms to adsorb molecular oxygen.Furthermore Co- N active sites can weaken the O—O bonds,and enhance the reduction of oxygen,and then complete the ORR through the 4e-reduction pathway,which provides a good explanation for the high electrocatalytic activity of our material.

关 键 词：聚苯并咪唑 三聚氰胺 非贵金属电催化剂 氧还原反应 质子交换膜燃料电池 

分 类 号：O643.36[理学—物理化学] TM911.4[理学—化学]