具有高活性和突出的抗中毒性能的Pt修饰Ru/C催化剂的制备和表征(英文)

采用两步浸渍-还原法制备了一种具有高Pt利用效率,高性能的Pt修饰的Ru/C催化剂(Ru@Pt/C).对于甲醇的阳极氧化反应,该催化剂的单位质量铂的催化活性分别为Pt/C、自制PtRu/C和商业JMPtRu/C催化剂的1.9、1.5和1.4倍;其电化学活性比表面积分别为Pt/C和自制PtRu/C的1.6和1.3倍.尤为重要的是该催化剂对甲醇氧化中间体具有很好的去除能力,其正向扫描的氧化峰的峰电流密度(If)与反向扫描氧化峰的峰电流密度(Ib)之比可高达2.4,为Pt/C催化剂的If/Ib的2.7倍,表明催化剂具有很好的抗甲醇氧化中间体毒化的能力.另外,Ru@Pt/C催化剂的稳定性也高于Pt/C、自制PtRu/C和商业JMPtRu/C催化剂的稳定性.采用X射线衍射(XRD)、透射电镜(TEM)和X射线光电子能谱(XPS)对催化剂进行了表征,Pt在Ru表面的包覆结构得到了印证.Ru@Pt/C的高铂利用效率、高性能和高抗毒能力使其有望成为一种理想的直接甲醇燃料电池电催化剂.

Preparation and Characterization of Platinum-Decorated Ru/C Catalyst with High Performance and Superior Poison Tolerance

A platinum-decorated Ru/C catalyst with high platinum utilization efficiency, high performance, and high poisoning tolerance was prepared using a two-stage impregnation reduction method. We found that for anodic methanol oxidation the catalyst activity in terms of the Ft load was 1.9 and 1.5 times as that of Pt/C and PtRu/C alloy catalysts, respectively. These values are also higher than that of the commercial JM PtRu/C catalyst. The electrochemically active surface area of Ru@Pt/C was found to be 1.6 and 1.3 times as those of Pt/C and PtRu/C alloy catalysts, respectively. Furthermore, we found that the ratio of the forward peak current density (It) to the backward peak current density (Ib) reached 2.4, which was 2.7 times as that of the Pt/C catalyst. This implies that the Pt-decorated Ru/C catalyst possesses a high tolerance for the intermediate poisoning species. In addition, the stability of Ru@Pt/C was higher than that of Pt/C, PtRu/ C alloy and JM PtRu/C. The catalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The core-shell structure of the catalyst was determined by XRD and TEM. The high performance and high poisoning tolerance of Ru@Pt/C during the anodic oxidation of methanol make it a promising electrocatalyst for direct methanol fuel cells.