摘要
选用具有高介孔表面积和高导电性能的碳黑Ketjen Black EC 300J(简称KB)作为载体,制备了碳黑负载钴卟啉(CoTMPP/KB),经过900℃热处理后得到电催化剂,用于燃料电池阴极氧还原反应.利用循环伏安法(CV)研究了碳载体不同预处理方法以及高温热处理对碳黑负载钴卟啉电催化剂的氧还原催化性能的影响.结果表明,6 mol/L HNO3预处理可以很好地改善KB性能,碳黑负载钴卟啉经过900℃热处理得到的电催化剂,虽然其中钴卟啉的结构发生了裂解,但催化剂具有较好的氧还原催化性能,阴极峰值电位(Ep)及最大电容电流(Ip)均为最佳.采用IR、XRD、TEM和氮吸附/脱附等手段对KB碳黑以及电催化剂表面性质及微观结构进行了分析,经6 mol/L HNO3预处理的KB碳黑表面羟基(—OH)等含氧基团增多,团聚不明显,平均粒径约30 nm;孔结构主要由孔径分布较窄的中孔组成,是一种较好的电催化剂载体;经900℃热处理后,电催化剂结构中有CoC3(101)和金属态Co(111)结构出现,钴离子在碳黑表面的分散较好,平均孔径为8.2 nm,比表面积为463.4 m2/g.
Carbon black EC 300J（KB） with high mesoporous area and electrical conductivity was used as support for cobalt tetramethoxyphenylporphyrin（CoTMPP） to prepare the cathode electrocatalysts（CoTMPP/KB） for the oxygen reduction in proton exchange membrane fuel cell（PEMFC）.The influence of chemical pretreatment of carbon black supports and 900 ℃ heat-treating of the electrocatalysts on the electrocatalytic activities for oxygen reduction of CoTMPP/KB were investigated by cyclic voltammogram（CV）.The results show that pretreatment with 6 mol/L HNO3 of carbon support and 900 ℃ heat-treatment of the catalyst,although the pyrolysis occurred for the CoTMPP structure,the electrocatalyst has the best catalytic performance for oxygen reduction,both the cathodic peak potential（Ep） and the maximum capacitive current（Ip） were improved.The surface properties and the microstructures of both the carbon black KB and the electrocatalyst were investigated by IR,XRD,TEM and nitrogen adsorption/desorption.After the pretreatment with 6 mol/L HNO3,the concentration of hydroxyl group and other oxygen-groups were increased on KB surface and no obvious particle aggregation of KB was observed,an average particle size of about 30 nm of KB was observed;The pore structure of the catalysts is mainly composed of mesopores and has a narrow pore size distribution,which prove CoTMPP/KB to be a good electrocatalyst;CoC3（101） and metallic Co（111） were formed in the catalyst after 900 ℃ heat-treatment,and the cobalt ions were well dispersed in the carbon black surface,with mean pore size of 8.2 nm and surface area of 463.4 m2/g.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第2期344-349,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:20871082
20471037)资助
