Fabrication and characterization of microtubular solid oxide cell supported with nanostructured mixed conducting perovskite fuel electrode

Mutual Conversion of CO-CO2 on a Perovskite Fuel Electrode with Endogenous Alloy Nanoparticles for Reversible Solid Oxide Cells

Reversible solid oxide cells (RSOCs) can efficiently render the mutual conversion between electricity and chemicals, for example, electrolyzing CO₂ to CO under a solid oxide electrolysis cell (SOEC) mode and oxidizing CO to CO₂ under a solid oxide fuel cell (SOFC) mode. Nevertheless, the development of RSOCs is still hindered, owing to the lack of catalytically active and carbon-tolerant fuel electrodes. For improving mutual CO-CO₂ conversion kinetics in RSOCs, here, we demonstrate a high-performing and durable fuel electrode consisting of redox-stable Sr₂(Fe, Mo)₂O_6-δ perovskite oxide and epitaxially endogenous NiFe alloy nanoparticles. The electrochemical impedance spectrum (EIS) and distribution of relaxation time (DRT) analyses reveal that surface/interface oxygen exchange kinetics and the CO/CO₂ activation process are both greatly accelerated. The assembled single cell produces a maximum power density (MPD) of 443 mW cm^-2 at 800 °C under the SOFC mode, with the corresponding CO oxidation rate of 5.524 mL min^-1 cm^-2. On the other hand, a current density of -0.877 A cm^-2 is achieved at 1.46 V under the SOEC mode, equivalent to a CO₂ reduction rate of 6.108 mL min cm^-2. Furthermore, reliable reversible conversion of CO-CO₂ is proven with no performance degradation in 20 cycles under SOEC (1.3 V) and SOFC (0.6 V) modes. Therefore, our work provides an alternative way for designing highly active and durable fuel electrodes for RSOC applications.

Progress of Exsolved Metal Nanoparticles on Oxides as High Performance (Electro)Catalysts for the Conversion of Small Molecules

Utilizing electricity and heat from renewable energy to convert small molecules into value-added chemicals through electro/thermal catalytic processes has enormous socioeconomic and environmental benefits. However, the lack of catalysts with high activity, good long-term stability, and low cost strongly inhibits the practical implementation of these processes. Oxides with exsolved metal nanoparticles have recently been emerging as promising catalysts with outstanding activity and stability for the conversion of small molecules, which provides new possibilities for application of the processes. In this review, it starts with an introduction on the mechanism of exsolution, discussing representative exsolution materials, the impacts of intrinsic material properties and external environmental conditions on the exsolution behavior, and the driving forces for exsolution. The performances of exsolution materials in various reactions, such as alkane reforming reaction, carbon monoxide oxidation, carbon dioxide utilization, high temperature steam electrolysis, and low temperature electrocatalysis, are then summarized. Finally, the challenges and future perspectives for the development of exsolution materials as high-performance catalysts are discussed.

New trends in the development of electrophoretic deposition method in the solid oxide fuel cell technology: theoretical approaches, experimental solutions and development prospects

The key features and challenges of the use of electrophoretic deposition for the formation of functional layers of solid oxide fuel cells are considered. Theoretical models and experimental results of the studies of electrophoretic deposition are presented. The analysis covers the physicochemical deposition mechanisms, methods for preparing suspensions and conditions necessary for obtaining thin-film electrode and protective single- and multi-layers with both dense and porous structure for solid oxide fuel cells. The prospects of theoretical simulations of the method and its potential practical applications are evaluated.

The bibliography includes 282 references.