超细Ni,Co—石墨层间化合物的制备及其电极催化性能

采用二步法先合成钾的石墨层间化合物，然后再通过它合成Ｃｏ，Ｎｉ系石墨层间化合物。化学分析、Ｘ射线衍射、Ｘ射线光电子能谱及透射电镜的分析结果表明，这些化合物中金属主要以正２价形态存在，化合物的粒度为纳米级。用微电极测试了它们在ＫＯＨ溶液中对氧还原的催化活性，发现Ｃ４８Ｃｏ及Ｃ４８Ｎｉ为好，尤以Ｃ４８Ｃｏ为优；加入Ｃ４８Ｃｏ的气体扩散电极的电流密度，比未加的高６８倍。用旋转圆盘电极研究了对氧的还原过程，发现该过程同时受扩散与化学反应两种作用的混合控制，反应电子数为２。

PREPARATION OF SUPERFINE Ni, Co GRAPHITE INTERCALATION COMPOUNDS AND THEIR CATALYST EFFECT

Graphite intercalation compounds(GICs) Co and GICs Ni have been successfully synthesized with the GICs K as intermediates, and the compounds have been analyzed with chemical analysis, X ray diffraction, X ray photoelectron spectroscopy(XPS), transmission electron microscopy(TEM). The valences of Co and Ni in the compounds are both 2. The particle size of these compounds is in the order of nm. The experimental results of powder microelectrodes indicated that C 48 Co is the best one for oxygen reduction among all the GICs Co and GICs Ni compounds studied. The soft embeded rotating disk electrode(RDE) experiments indicated oxygen reduction on the surface of GICs Co is jointly controlled by diffusion and electrochemical reaction, the number of electron transfer of oxygen reduction is 2. The preparation of peroxides using gas diffusion electrodes with catalyst C 48 Co indicated that the cathodic current density is 68 times higher than that without C 48 Co, the current efficiency is 93%.