释放A位点Ca-合LaCo0.2Fe0.8O3-δ的潜力:一种具有氧稳定的阴极材料,可在直接CO2电解中实现高电流密度
Haixia Li1, Wanhua Wang1, Lucun Wang2
1Department of Mechanical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States.
ACS applied materials & interfaces
|September 6, 2023
概括
这项研究开发了用于固体氧化物电解细胞的新型Ca-化矿阴极,显著提高了直接二氧化碳电解效率. 这些新材料提供了一种可再生的解决方案,以减少二氧化碳排放并提高环境可持续性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 环境工程 环境工程
背景情况:
- 大规模的二氧化碳 (CO2) 排放带来了环境可持续性的挑战.
- 固体氧化物电解电池 (SOEC) 是利用可再生能源转化二氧化碳的一个有希望的途径.
- 在SOEC中,含有的阴极会受到碳化,阻碍效率和稳定性.
研究的目的:
- 开发新型的A位点Ca-doped La1-xCaxCo0.2Fe0.8O3-δ (LCCF) 矿氧化物作为中温SOEC (IT-SOEC) 中直接CO2电解的高效阴极.
- 研究LCCF阴极的二氧化碳电解性能和长期稳定性,解决碳化的挑战.
主要方法:
- 合成和表征A位点Ca-合La1-xCaxCo0.2Fe0.8O3-δ (0.2 ≤ x ≤ 0.6) 的矿氧化物.
- 用LCCF64作为阴极和LSGM电解液的电解细胞的制造和测试.
- 评估电化学性能,包括极化电阻和电流密度,在800°C的二氧化碳大气中.
- 在直接二氧化碳电解过程中评估细胞稳定性.
主要成果:
- 在纯二氧化碳大气中,La0.6Ca0.4Co0.2Fe0.8O3-δ (LCCF64) 阴极在0.18 Ω cm2的低极化电阻中实现了低极化电阻.
- 在800°C的LSGM支持电解电池中,在1.5V时获得了2.24 A cm-2的显著电流密度,使用LCCF64作为阴极.
- 带有LCCF64电极的对称电池表现出有希望的电解性能 (1.78 A cm-2在1.5 V和800 °C).
- 在直接二氧化碳电解过程中,在800°C的0.5 A cm−2恒流下,实现了稳定的电池性能.
- 由于形成易于移除的碳酸盐中间体,LCCF64显示出作为可再生阴极的潜力.
结论:
- 化LCCF64矿氧化物是IT-SOEC中直接CO2电解的高效阴极材料,克服了碳化问题.
- 卓越的性能归因于在现场溶解的Co/CoFe纳米颗粒和额外的氧气空缺的协同效应,创造了二氧化碳吸附和电解的活性场所.
- 本研究提出了一种新的策略,用于设计高性能,可再生的催化剂,以实现高效的二氧化碳转化.
相关概念视频
Ladder Diagrams: Redox Equilibria
477
Ladder diagrams are useful tools for understanding redox equilibrium reactions, especially the effects of concentration changes on the electrochemical potential of the reaction. The vertical axis in the redox ladder diagrams represents the electrochemical potential, E. The area of predominance is demarcated using the Nernst equation.
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
477
Electrolysis
26.6K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
26.6K
Electrodeposition
663
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...
663
Controlled-Current Coulometry: Overview
235
Controlled current coulometry, also known as amperostatic coulometry, is a technique used in electrochemical analysis to measure the quantity of a substance through the controlled passage of current. It involves the application of a constant current to an electrochemical cell containing the analyte of interest. As the current flows through the cell, the analyte undergoes a redox reaction at the electrode surface, resulting in a charge transfer. By monitoring the time required for a certain...
235
Controlled-Potential Coulometry: Electrolytic Methods
202
Controlled-potential coulometry, also known as potentiostatic coulometry, employs a three-electrode system in which the working electrode's potential is precisely regulated using a potentiostat. Platinum working electrodes are utilized for positive potentials, while mercury pool electrodes are favored for extremely negative potentials. The platinum counter electrode is separated from the analyte using a membrane or salt bridge to avoid interference in the analysis.
The chosen potential...
The chosen potential...
202


