方形γ-MnOOH的制备及其电催化氧还原的性能

Preparation and electrocatalytic oxygen reduction performance characterization of prismatic γ-MnOOH

寻找新型锰氧化物作为锌-空气电池阴极氧还原催化剂是电化学工作者的研究目标之一。在150℃水热条件下,用HMnO4氧化Mn(CH3COO)2,反应产物通过X射线衍射仪(XRD)、扫描电镜(SEM)测试表明为方形γ-MnOOH。分别用方形γ-MnOOH和电解二氧化锰(EMD)做氧电极催化剂冷压制成气体扩散电极,稳态极化测试结果表明:γ-MnOOH的电极电位比EMD正移30～60mV,当催化膜中w(γ-MnOOH)为25%时催化活性最高。使用γ-MnOOH作为催化剂的锌-空气电池,在40mA/cm2电流密度下工作电压达到1.23V。

The research of new manganese oxides as electro-catalysts for the oxygen reduction reaction is one of important goals of the electrochemistry and catalysis community. Manganese oxide was synthesized by oxidizing Mn （CH3COO）2 with HMnO4at 150 ℃. The synthesized samples were shown as prismatic crystal γ-MnOOH by XRD and SEM. The gas diffusion electrode was obtained by cold-pressing. Electrochemical performances of the electrodes were studied by current-potential polarization curves. Air electrode potential can be improved by 30-60 mV, as compared with the catalysts supported on EMD, and the results show adding 25% content of γ-MnOOH can gain optimal performance,the polarization is smallest. At the typical current density 40 mA/cm^2 of zinc - air battery, the working voltage plateau of the cell with γ-MnOOH is about 1.23 V.