A mesoporous catalytic fiber architecture decorated by exsolved nanoparticles for reversible solid oxide cells

Abstract

Along the way to developing highly active catalysts, the fabrication of unique architectures is significant in determining the performance of energy conversion and storage devices. One of the highly competitive options is surface-modified with dispersed nanoparticles by an simply in-situ growth strategy. Typically, the exsolution of active nanoparticles is demonstrated in the irregular powders of perovskite oxides. Here, we report the rational design and fabrication of a porous A-site-deficient titanate fiber decorated by exsolved Ni nanoparticles as a highly efficient and robust fuel electrode for solid oxide cells. We find that the porosity of fiber is one of the pronounced effects on the Ni exsolution. Based on the finite element simulation method and experiments, it is demonstrated that the addition of Gd0.1Ce0.9O2 (GDC) in fibrous fuel electrode enhances the contact and connectivity between fibers. This unique microstructure not only provides high specific surface area and more active sites but also benefits to easier mass transfer and charge transfer, resulting in a much lower polarization resistance. The corresponding device shows superior electrochemical performance and durability in humified H2 (3% H2O). This highly active and robust fuel electrode together with the unique architectures lays a strong foundation for designing high-electrochemical active devices.