摘要
采用化学氧化法在苯胺聚合过程中分别加入钴(Co)为Co2+而阴离子基团为(C2H3O2)22-、Cl22-、(NO3)22-、SO42-及C2O42-的乙酸钴、氯化钴、硝酸钴、硫酸钴、草酸钴等钴盐,合成出不同聚苯胺-钴(PANI-Co)配位聚合物。然后将PANI-Co聚合物作为前驱体在N2气氛中900℃热处理,制备出氮掺杂的Co-N-C碳基催化剂。采用SEM、XRD、XPS、Raman等手段分析Co-N-C催化剂的形貌、结构、化学组成及化学价态,并采用电化学方法测试了Co-N-C催化剂的电催化活性。结果表明,Co盐的阴离子基团对Co-N-C催化剂的形貌影响不大,但对Co-N-C催化剂中表面化学组成及含量、碳结构、石墨化程度以及Co的价态影响较大,并且Co盐的阴离子基团会影响Co-N-C催化剂的电催化活性,其氧还原(ORR)活性按照(C2H3O2)22->Cl22->(NO3)22->SO42->C2O42-顺序降低。含(C2H3O2)22-和Cl22-阴离子的钴盐制备的Co-N-C催化剂具有较高的ORR活性,这可能源于其较高含量的石墨氮和吡啶氮。
During the process of the aniline polymerization,bivalent cobalt salt with different anionic groups such as(C 2H 3O 2)2 2-,Cl 2 2-,(NO 3)2 2-,SO 4 2-and C 2O 4 2-were added into the solution and then different polyaniline cobalt(PANI-Co)coordination polymer were obtained.Finally,Co-N-C catalysts were prepared through pyrolysis of PANI-Co coordination polymer.The morphology,structure,chemical composition and chemical valence of the Co-N-C catalysts were characterized by scanning electron microscopy(SEM),X-ray spectroscopy(XRD),X-ray photoelectron spectroscopy(XPS)and Raman spectra(Raman).The electrocatalytic activity of Co-N-C catalysts were tested by electrochemical method.The results showed that the cobalt salt anionic groups had little impact on the morphology of Co-N-C catalysts,but had a great influence on the composition and surface chemistry of Co-N-C catalysts,carbon structure,degree of graphitization and the valence of Co.The cobalt salt anionic groups could affect the electrocatalytic activity of Co-N-C catalysts.The catalytic activities decreased as(C 2H 3O 2)2 2->Cl 2 2->(NO 3)2 2->SO 4 2->C 2O 4 2-.The Co-N-C catalysts prepared by cobalt salt containing(C 2H 3O 2)2 2-and Cl 2 2-anions had higher ORR activity,which possibly due to the higher content of graphite nitrogen and pyridine nitrogen.
作者
夏艺萌
吴帅
谭丰
李卫
魏清茂
闵春刚
杨喜昆
XIA Yimeng;WU Shuai;TAN Feng;LI Wei;WEI Qingmao;MIN Chungang;YANG Xikun(College of Material Science and Engineering,Kunming University of Science and Technology,Kunming 650093;Research Center for Analysis and Measurement,Kunming University of Science and Technology,Kunming 650093)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第3期362-367,372,共7页
Materials Reports
基金
国家自然科学基金(21363012
51374117)
