1. Rare-earth doped cerium oxides for steam electrolysis under ultra-low voltage intensified by methane oxidation at anodes.
- Author
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Liu, Yuxin, Lu, Houfang, Hu, Qiang, Zhou, Liming, Wu, Kejing, Zhou, Jinlong, and Liang, Bin
- Subjects
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CERIUM oxides , *HIGH temperature electrolysis , *ELECTROLYTIC oxidation , *RARE earth ions , *OXYGEN evolution reactions , *STEAM reforming , *ANODES , *HYDROGEN oxidation - Abstract
Oxygen evolution reaction at the anode consumes about 60–70% of the total power for the solid oxide electrolysis cell (SOEC), and power consumption can be greatly reduced by introducing hydrocarbon fuels such as methane into the anode for the oxidation reaction. In this work, rare-earth doped CeO 2 is used as catalyst support and oxygen ion conductor with Ni serving as an active metal for methane oxidation at the SOEC anode. The catalyst is synthesized via stepwise hydrolysis and impregnation methods, and the influences of rare-earth oxides on the performance of CH 4 thermal oxidation, SOEC anode oxidation and hydrogen production are studied. The results show that 5%Ni–Ce 0.8 Gd 0.2 O 2-δ exhibits the optimal catalytic oxidation and electrolytic hydrogen production with the lowest cell voltage of 0.38 V at 0.4 A/cm2. The high performance is mainly attributed to the oxygen vacancy, oxygen ion conductivity, and active metal dispersion. It is supposed that oxygen evolution reaction and simultaneous methane oxidation with generated oxygen occur at the SOEC anode can reduce oxygen partial pressure, which results in the ultra-low voltage for hydrogen production. [Display omitted] • Optimized oxygen vacancy and oxygen ion conductivity of rare-earth doped CeO 2 enhance the electrochemical oxidation. • The SOEC anode of Gd-doped CeO 2 realizes an ultra-low voltage of 0.38 V at 0.4 A/cm2. • OER and subsequently CH 4 oxidation is proposed for anode reactions to reduce operation voltage. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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