Abstract

The work is devoted to investigation of the electrochemical behavior of (Fe,Ni)O_x-based composite anodes in the hydrogen- and methane-containing fuel. Among the studied composites, the optimum electrochemical characteristics were observed for anodes with Fe : Ni ratio approaching 2. In particular, for the electrodes with initial composition 50 vol % Fe_0.67Ni_0.33O_х–50 vol % Zr_0.85Y_0.15O_1.93 the anode overpotential equals 20–30 mV at a current density of 50–80 mA/cm² in 10% Н₂–Ar–H₂O at relatively low temperatures (873–923 K). Increasing current leads to further activation, presumably due to a partial oxidation of metallic particles located at the anode surface. However, the microstructure degradation of the anode layers still represents a significant problem for their utilization. Testing of the electrocatalytic activity of the anodes fabricated from Ni, Zr_0.83Sc_0.17O_1.92 (ScSZ) and Ce_0.9Gd_0.1 O_{2 – δ} (GDC) revealed a high activity toward catalytic partial methane oxidation with the subsequent electrochemical oxidation of the conversion products, as well as formation of carbonaceous deposits at the nickel surface. The methane conversion degree on Ni-anode comes to 60–90% and decreases with time and on cooling. The doping of nickel oxide with iron lowers the conversion degree and promotes the carbon poisoning, supposedly, because of the lowering of the anodic current density resulting from the worsening of the electrochemical activity.

中文翻译：

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含甲烷大气中固体氧化物燃料电池基于（Fe，Ni）O x的阳极的电化学行为

摘要

这项工作致力于研究含氢和甲烷的燃料中基于（Fe，Ni）O _x的复合阳极的电化学行为。在所研究的复合材料，观察到最佳的电化学特性为阳极与Fe和Ni的比例接近2特别地，对于与初始组合物50体积％的Fe电极_0.67的Ni _0.33 ö _х -50体积％的Zr _0.85 ý _0.15 Ò _1.93的阳极过电位的equals 20-30毫伏在50-80毫安/厘米的电流密度²在10％Н ₂ -Ar-H ₂O在相对较低的温度下（873–923 K）。电流的增加可能导致进一步的激活，这大概是由于位于阳极表面的金属颗粒的部分氧化所致。然而，阳极层的微观结构退化仍然代表着其利用的重大问题。由Ni，Zr _0.83 Sc _0.17 O _1.92（ScSZ）和Ce _0.9 Gd _0.1 O _2-δ制成的阳极的电催化活性测试（GDC）显示出对催化的部分甲烷氧化具有高活性，随后转化产物进行了电化学氧化，并且在镍表面形成了碳质沉积物。镍阳极上的甲烷转化率达到60-90％，并随时间和冷却而降低。据推测，由于电化学活性的恶化导致阳极电流密度的降低，因此用铁掺杂氧化镍会降低转化率并促进碳中毒。