CSIR-Central Electrochemical Research Institute-Madras Unit, CSIR Complex, Chennai, 600 113, India.
Phys Chem Chem Phys. 2012 Jul 21;14(27):9683-95. doi: 10.1039/c2cp40655a. Epub 2012 Jun 13.
Carbon supported PdCo catalysts in varying atomic ratios of Pd to Co, namely 1 : 1, 2 : 1 and 3 : 1, were prepared. The oxygen reduction reaction (ORR) was studied on commercial carbon-supported Pd and carbon-supported PdCo nanocatalysts in aqueous 0.1 M KOH solution with and without methanol. The structure, dispersion, electrochemical characterization and surface area of PdCo/C were determined by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Cyclic Voltammetry (CV), respectively. The electrochemical activity for ORR was evaluated from Linear Sweep Voltammograms (LSV) obtained using a rotating ring disk electrode. The catalysts were evaluated for their electrocatalytic activity towards oxygen reduction reaction (ORR) in Alkaline Polymer Electrolyte Membrane Fuel Cells (APEMFCs). PdCo(3 : 1)/C gives higher performance (85 mW cm(-2)) than PdCo(1 : 1)/C, PdCo(2 : 1)/C and Pd/C. The maximum electrocatalytic activity for ORR in the presence of methanol was observed for PdCo(3 : 1)/C. First principles calculations within the framework of density functional theory were performed to understand the origin of its catalytic activity based on the energy of adsorption of an O(2) molecule on the cluster, structural variation and charge transfer mechanism.
制备了不同钯钴原子比（1:1、2:1 和 3:1）的碳负载 PdCo 催化剂。在含有和不含有甲醇的 0.1 M KOH 水溶液中，研究了商业碳负载 Pd 和碳负载 PdCo 纳米催化剂上的氧还原反应（ORR）。通过 X 射线衍射（XRD）、透射电子显微镜（TEM）和循环伏安法（CV）分别确定了 PdCo/C 的结构、分散、电化学特性和比表面积。通过旋转环盘电极获得的线性扫描伏安法（LSV）评估了 ORR 的电化学活性。评估了催化剂在碱性聚合物电解质膜燃料电池（APEMFCs）中对氧还原反应（ORR）的电催化活性。PdCo(3:1)/C 的性能（85 mW cm(-2))高于 PdCo(1:1)/C、PdCo(2:1)/C 和 Pd/C。在存在甲醇的情况下，PdCo(3:1)/C 对 ORR 的最大电催化活性。基于团簇上 O(2)分子的吸附能、结构变化和电荷转移机制，利用密度泛函理论中的第一性原理计算，解释了其催化活性的起源。
