Department of Chemistry, Centre of Advanced Study, Faculty of Science, Banaras Hindu University, Varanasi-221005, India.
Phys Chem Chem Phys. 2013 Dec 14;15(46):20333-44. doi: 10.1039/c3cp53880j.
Hybrid materials comprising of Pd, MCo2O4 (where M = Mn, Co or Ni) and graphene have been prepared for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells. Structural and electrochemical characterizations were carried out using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, chronoamperometry and cyclic, CO stripping, and linear sweep voltammetries. The study revealed that all the three hybrid materials are active for both methanol oxidation (MOR) and oxygen reduction (ORR) reactions in 1 M KOH. However, the Pd-MnCo2O4/GNS hybrid electrode exhibited the greatest MOR and ORR activities. This active hybrid electrode has also outstanding stability under both MOR and ORR conditions, while Pt- and other Pd-based catalysts undergo degradation under similar experimental conditions. The Pd-MnCo2O4/GNS hybrid catalyst exhibited superior ORR activity and stability compared to even Pt in alkaline solutions.
已制备出包含 Pd、MCo2O4（其中 M = Mn、Co 或 Ni）和石墨烯的杂化材料，将其用作碱性直接甲醇燃料电池中的高效双功能电催化剂。使用 X 射线衍射、透射电子显微镜、X 射线光电子能谱、计时电流法和循环伏安法、CO 剥离和线性扫描伏安法对结构和电化学性质进行了研究。研究表明，所有三种杂化材料在 1 M KOH 中均对甲醇氧化 (MOR) 和氧还原 (ORR) 反应具有活性。然而，Pd-MnCo2O4/GNS 杂化电极表现出最大的 MOR 和 ORR 活性。在 MOR 和 ORR 条件下，这种活性杂化电极也具有出色的稳定性，而 Pt 和其他基于 Pd 的催化剂在类似的实验条件下会发生降解。与碱性溶液中的 Pt 相比，Pd-MnCo2O4/GNS 杂化催化剂表现出更高的 ORR 活性和稳定性。
