Ni–Fe–La(Sr)Fe(Mn)O3 as a New Active Cermet Cathode for Intermediate‐Temperature CO2 Electrolysis Using a LaGaO3‐Based Electrolyte
Ni–Fe–La(Sr)Fe(Mn)O3 as a New Active Cermet Cathode for Intermediate‐Temperature CO2 Electrolysis Using a LaGaO3‐Based Electrolyte
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DOI：
10.1002/aenm.201401003
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发表时间：
2015
影响因子：
27.8
通讯作者：
Shijing Wang;H. Tsuruta;M. Asanuma;T. Ishihara
中科院分区：
文献类型：
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作者：
Shijing Wang;H. Tsuruta;M. Asanuma;T. Ishihara
研究了Ni-Fe体系的各种添加剂作为金属陶瓷阴极用于使用La0.9Sr0.1Ga0.8Mg0.2O3（LSGM）电解质的CO2电解（973-1173 K），就离子传输数和电导率而言，La0.9Sr0.1Ga0.8Mg0.2O3（LSGM）电解质是中温固体氧化物电解电池最有前途的氧化物离子导体之一。发现Ni-Fe-La0.6Sr0.4Fe0.8Mn0.2O3（Ni-Fe-LSFM）在1.6 V和1073 K下的电流密度为2.32 A cm−2时表现出显著的性能。将LSFM粉末与Ni-Fe混合后，阴极过电位显著降低，这与CO2还原反应位点的数量增加有关。对于Ni-Fe-LSFM，在高温下在CO2电解条件下比Ni-Fe维持小得多的颗粒（<200 nm）。X射线衍射分析表明Ni-Fe-LSFM的主要相是Ni和LaFeO 3;因此，LaFeO 3的氧化物相在CO2电解过程中也得以保持。气体产物的分析表明，只有CO形成，CO形成的速率与四电子还原过程的速率一致，表明CO2还原为CO是选择性的。实验还证实，在CO2电解后，Ni-Fe-LSFM阴极上几乎没有焦炭沉积。
Various additives to Ni–Fe systems are studied as cermet cathodes for CO2 electrolysis (973–1173 K) using a La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) electrolyte, which is one of the most promising oxide‐ion conductors for intermediate‐temperature solid‐oxide electrolysis cells in terms of ionic‐transport number and conductivity. It is found that Ni–Fe–La0.6Sr0.4Fe0.8Mn0.2O3 (Ni–Fe–LSFM) exhibits a remarkable performance with a current density of 2.32 A cm−2 at 1.6 V and 1073 K. The cathodic overpotential is significantly decreased by mixing the LSFM powder with Ni–Fe, which is related to the increase in the number of reaction sites for CO2 reduction. For Ni–Fe–LSFM, much smaller particles (<200 nm) are sustained under CO2 electrolysis conditions at high temperatures than for Ni–Fe. X‐ray diffraction analysis suggests that the main phases of Ni–Fe–LSFM are Ni and LaFeO3; thus, the oxide phase of LaFeO3 is also maintained during CO2 electrolysis. Analysis of the gaseous products indicates that only CO is formed, and the rate of CO formation agrees well with that of a four‐electron reduction process, suggesting that the reduction of CO2 to CO proceeds selectively. It is also confirmed that almost no coke is deposited on the Ni–Fe–LSFM cathode after CO2 electrolysis.