一维/二维复合碳载体组成对Pd催化剂甲醇氧化性能的影响

采用固相-液相两步混合法制备了由碳纳米管（CNTs）和石墨烯纳米片（GNPs）组成的CNTs-GNPs复合载体。以乙二醇还原法将Pd纳米粒子沉积于复合碳载体上，制得Pd/CNTs-GNPs催化剂。以透射电子显微镜、X射线衍射及X射线光电子能谱表征催化剂的形貌、组成和结构；以电化学方法考察催化剂的甲醇电氧化性能。结果表明，Pd/CNTs-GNPs（1/4）（GNPs质量分数为1/4）催化剂具有较大的电化学表面积和较高的甲醇电氧化活性，其甲醇氧化峰电流密度可达Pd/CNTs催化剂的1.97倍。催化剂的高活性得益于CNTs-GNPs载体的一维/二维复合结构使Pd纳米粒子具有良好的分散性能。计时电流实验表明，与单一载体负载Pd催化剂相比，复合载体负载Pd催化剂具有较强的抗中毒能力。

Effect of One-Dimensional/Two-Dimensional Composite Carbon Support on Methanol Oxidation Performance of Pd Catalysts

CNTs-GNPs, hybrid support composed of carbon nanotubes (CNTs) and graphene nanoplates (GNPs) was prepared by a solid phase-liquid phase two-step mixing method. The Pd/CNTs-GNPs catalyst was prepared by deposition of Pd nanoparticles on composite carbon support by the ethylene glycol reduction method. The morphologies, compositions, and structures of catalysts were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The performances of catalysts for methanol electrooxidation were investigated by electrochemical methods. The results showed that Pd/CNTs-GNPs(1/4) (the mass fraction of GNPs was 1/4) catalyst exhibited a large electrochemical surface area and high performances for methanol electrooxidation, and its peak current density of methanol oxidation was 1.97 times that of the Pd/CNTs catalyst. The high activity of the catalyst is attributed to the good dispersion of Pd nanoparticles on the one-dimensional/two-dimensional composite CNTs-GNPs support. The chronoamperometry test showed that Pd catalysts supported on the CNTs-GNPs hybrid support had stronger anti-poisoning abilities as compared to the Pd catalyst supported on a single carbon support.