Electrocatalytic Activity of layred transition-metal oxides for the anodic oxidation of methane.

研究了甲烷直接电化学氧化的新型负极材料。LiMn2O4尖晶石可以转化为HMn2O4，对甲烷和丁烷的气相氧化表现出很高的催化活性。这种高活性是由于质子以氢的形式脱附在表面的特殊价态造成的。研究发现，过渡金属离子的比表面价态对燃料的催化氧化和电催化氧化是有效的。将多种氧离子导电电解液与新型负极材料相结合，研究了电池的电催化反应。质子交换的过渡金属氧化物及其3d和4d组合金属的质子脱附增强了HCoO_2和HCRO_2阳极氧化氢气和PdCoO_2阳极氧化甲烷的电催化活性。过渡金属离子的价态使氢和甲烷能够有效地与通过电解液传输的氧离子反应。层状过渡金属氧化物作为阳极的这一特性导致在低于约900ﾟC的较低温度下产生高功率密度。

New anode materials capable of the direct electrochemical oxidation of methane have been investigated. The LiMn_2O_4 spinel can be converted to HMn_2O_4, which shows a high catalytic activity for the gaseous oxidation of methane and butane. The high activity is caused by the specific valence state of teh surface Mnions due to the desorption of protons as hydrogen. The specific surface valence state of transition metal ions was found to be effective for the catalytic and electrocatalytic oxidation of fuels. Electrocatlytic reactions was investigated for the cells using a number of oxygen ion conductive electrolyte combined with the new anode materials. The proton desorption from the proton-exchanged transition metal oxideds and the combination 3d and 4d metals enhance the electrocatalytic activity for the anodic oxidation reaction of hydrogen by HCoO_2 and HCrO_2 and methane by PdCoO_2. The valence states of the transition metal ions allow hydrogen and methane to react efficiently with the oxygem ions transported through the electrolytes. This property of the layred transition metal oxides as the anode results in the genaration of high power density at alower temperatures below about 900ﾟC.