CAJ | 학술논문

采用脉冲微波辅助化学还原法制备了钴-聚吡咯-碳(Co-PPy-C)载Pt催化剂(Pt/Co-PPy-C),其中Pt的总质量占20%.利用透射电镜(TEM)、光电子射线能谱分析(XPS)和X射线衍射(XRD)研究了催化剂的结构,用循环伏安(CV)、线性扫描伏安(LSV)等方法考察了其电化学活性及氧还原反应(ORR)动力学特性及耐久性. Pt/Co-PPy-C电催化剂的金属颗粒直径约1.8 nm,略小于商用催化剂Pt/C(JM)颗粒尺寸(约2.5 nm)；催化剂在载体上分散均匀,粒径分布范围较窄. Pt/Co-PPy-C的电化学活性比表面积(ECSA)(75.1 m2?g-1)高于商用催化剂的ECSA (51.3 m2?g-1). XPS测试表明,自制催化剂表面的Pt主要以零价形式存在.而XRD结果显示,自制催化剂中Pt(111)峰最强, Pt主要为面心立方晶格. Pt/Co-PPy-C具有与Pt/C(JM)相同的半波电位；在0.9 V下, Pt/Co-PPy-C的比活性(1.21 mA?cm-2)高于商用催化剂的比活性(1.04 mA?cm-2),表现出更好的ORR催化活性.动力学性能测试表明催化剂的ORR反应以四电子路线进行. CV测试1000圈后, Pt/Co-PPy-C和Pt/C(JM)的ECSA分别衰减了13.0%和24.0%,可见自制催化剂的耐久性高于商用Pt/C(JM),在质子交换膜燃料电池(PEMFC)领域有一定的应用前景.
채용맥충미파보조화학환원법제비료고-취필각-탄(Co-PPy-C)재Pt최화제(Pt/Co-PPy-C),기중Pt적총질량점20%.이용투사전경(TEM)、광전자사선능보분석(XPS)화X사선연사(XRD)연구료최화제적결구,용순배복안(CV)、선성소묘복안(LSV)등방법고찰료기전화학활성급양환원반응(ORR)동역학특성급내구성. Pt/Co-PPy-C전최화제적금속과립직경약1.8 nm,략소우상용최화제Pt/C(JM)과립척촌(약2.5 nm)；최화제재재체상분산균균,립경분포범위교착. Pt/Co-PPy-C적전화학활성비표면적(ECSA)(75.1 m2?g-1)고우상용최화제적ECSA (51.3 m2?g-1). XPS측시표명,자제최화제표면적Pt주요이령개형식존재.이XRD결과현시,자제최화제중Pt(111)봉최강, Pt주요위면심립방정격. Pt/Co-PPy-C구유여Pt/C(JM)상동적반파전위；재0.9 V하, Pt/Co-PPy-C적비활성(1.21 mA?cm-2)고우상용최화제적비활성(1.04 mA?cm-2),표현출경호적ORR최화활성.동역학성능측시표명최화제적ORR반응이사전자로선진행. CV측시1000권후, Pt/Co-PPy-C화Pt/C(JM)적ECSA분별쇠감료13.0%화24.0%,가견자제최화제적내구성고우상용Pt/C(JM),재질자교환막연료전지(PEMFC)영역유일정적응용전경.
Pt/cobalt-polypyrrole-carbon (Co-PPy-C)-supported catalysts were successful y prepared by pulse-microwave assisted chemical reduction. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) techniques were used to characterize the catalyst microstructure and morphology. The electrocatalytic performance, kinetic characteristics of the oxygen reduction reaction (ORR), and durability of the catalysts were measured by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) techniques. It was found that the particle size of Pt/Co-PPy-C was about 1.8 nm, which was smal er than that of commercial Pt/C (JM) catalysts (2.5 nm). The metal particles were wel-dispersed on the carbon support. The electrochemical specific area (ECSA) of Pt/Co-PPy-C (75.1 m2?g-1) was much higher than that of Pt/C (JM) (51.3 m2?g-1). The results of XPS showed that most of the Pt in the catalysts was in the Pt(0) state, and XRD results showed that the form of Pt was mainly the face-centered cubic lattice. The Pt/Co-PPy-C catalyst had the same half-wave potential as Pt/C (JM) and showed higher ORR activity. The Pt/Co-PPy-C catalyst proceeded by an approximately four-electron pathway in acid solution. After 1000 cycles of CV, the ECSA attenuation rates of Pt/Co-PPy-C and Pt/C were 13.0%and 24.0%respectively, which means that the Pt/Co-PPy-C catalyst has higher durability. The high performance of Pt/Co-PPy-C makes it a promising catalyst for proton exchange membrane fuel cells.