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采用微波辅助乙二醇法制备了一系列酸处理后的不同管径(8–15,20–30,30–50,>50 nm)的碳纳米管(CNT)负载铂(Pt)催化剂(Pt/CNT)。通过X射线光电子能谱(XPS)、X射线衍射(XRD)、热重分析仪(TGA)、透射电子显微镜(TEM)对所制得催化剂进行结构表征;采用循环伏安法(CV)和线性扫描伏安法(LSV)对其催化性能进行测试。结果表明,不同管径的碳纳米管对Pt的粒径、载量和分散性有一定程度影响;然而,不同CNT管径的催化剂表现出明显不同的催化氧还原反应(ORR)活性。采用管径为8–15 nm的CNT作为载体制备的催化剂(Pt/CNT_8)的Pt载量最高,表现出有很好的催化活性和稳定性。Pt/CNT8在0.9 V时Pt的质量活性为0.188 A?mg~(-1),是商业催化剂(JM Pt/C)的2倍。经扫描5000圈稳定性测试之后,Pt/CNT_8的半波电位负移(~7 mV)远远小于商业JM Pt/C半波电位的负移(~32 mV),表现出优越的催化ORR稳定性。
A series of carbon nanotubes (CNTs) supported Pt catalysts with different diameter (8-15, 20-30, 30-50,> 50 nm) were prepared by microwave assisted glycol method / CNT). The prepared catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) Its catalytic performance was tested by scanning voltammetry (LSV). The results show that CNTs with different diameters have a certain influence on the particle size, loading and dispersibility of Pt. However, catalysts with different CNTs exhibit significantly different catalytic ORR activity. The Pt catalyst prepared by using CNTs with diameter of 8-15 nm as carrier (Pt / CNT_8) has the highest Pt loading and shows good catalytic activity and stability. The mass activity of Pt at 0.9 V was 0.188 A? Mg ~ (-1), which was twice that of the commercial catalyst (JM Pt / C). The negative shift (~ 7 mV) of the half-wave potential of Pt / CNT_8 was much less than the negative shift (~ 32 mV) of the commercial JM Pt / C half-wave potential after a scan of 5000 lap stability tests and showed superior catalytic ORR stability Sex.