Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
J Am Chem Soc. 2012 Oct 17;134(41):16959-62. doi: 10.1021/ja307814j. Epub 2012 Oct 8.
Transition-metal oxide and phosphate materials, commonly used for lithium battery devices, are active as oxygen evolution reaction (OER) catalysts under alkaline and neutral solution conditions. Electrodes composed of LiCoO(2) and LiCoPO(4) exhibit progressive deactivation and activation for OER catalysis, respectively, upon potential cycling at neutral pH. The deactivation of LiCoO(2) and activation of LiCoPO(4) are coincident with changes in surface morphology and composition giving rise to spinel-like and amorphous surface structures, respectively. The amorphous surface structure of the activated LiCoPO(4) is compositionally similar to that obtained from the electrodeposition of cobalt oxide materials from phosphate-buffered electrolyte solutions. These results highlight the importance of a combined structural and electrochemical analysis of the materials surface when assessing the true nature of the OER catalyst.
过渡金属氧化物和磷酸盐材料通常用于锂电池设备，在碱性和中性溶液条件下可用作析氧反应 (OER) 催化剂。在中性 pH 下进行电位循环时，由 LiCoO(2) 和 LiCoPO(4) 组成的电极分别表现出对 OER 催化的渐进失活和激活。LiCoO(2) 的失活和 LiCoPO(4) 的激活与表面形貌和组成的变化一致，分别导致尖晶石状和无定形表面结构。活化的 LiCoPO(4) 的无定形表面结构在组成上与从磷酸盐缓冲电解质溶液中电沉积钴氧化物材料获得的结构相似。这些结果强调了在评估 OER 催化剂的真实性质时对材料表面进行综合结构和电化学分析的重要性。
