作　　者： (于景华）; (李文文）; (朱红）;

机构地区： 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： 《物理化学学报》 2017年第9期1838-1845,共8页

摘　　要： 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 nanocatalysts consisting of acid treated carbon nanotubes （CNTs） with different diameters （8-15, 20-30, 30-50, 〉50 nm） supporting platinum （Pt） nanoparticles （Pt/CNTs） were synthesized via a microwave-assisted ethylene glycol method. The as-synthesized catalysts were characterized by X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, thermogravimetric analysis （TGA）, and transmission electron microscopy （TEM）. Their catalytic performances in the oxygen reduction reaction （ORR） were evaluated by cyclic voltammetry （CV） and linear sweep voltammetry （LSV） The experimental results showed that the diameter of the CNTs influences the particle size, loading, and dispersion of Pt NPs. Furthermore, the Pt/CNTs having different CNT diameters displayed different catalytJc activities in the ORR. The catalyst Pt/CNTe, which was prepared by using CNTs with diameters ranging between 8-15 nm as the support, exhibited the highest Pt loading, catalytic activity, and stability in the ORR. The mass activity of Pt/CNT8 was determined to be 0.188 A.mg^-1 at 0.9 V, which is folds higher than that of the commercially available JM Pt/C catalyst. After testing the stability for 5000 potential cycles the negative shift （-7 mV） of the half-wave potential for Pt/CNT8 was found to be significantly lesser than that for the JM Pt/C catalyst （-32 mV）, indicating superior catalytic stability.

关 键 词： 微波辅助 铂 碳纳米管 管径效应 稳定性