In-situ construction of ceria-metal/titanate heterostructure with controllable architectures for efficient fuel electrochemical conversion

Abstract

Construction of ceria-metal/titanate heterostructure via exsolution is a promising strategy to improve the catalytic activity of titanate perovskites and broaden their applications in various energy conversion scenarios. However, the species exsolved after reduction are limited to reducible metal cations, such as Ni, Co, Fe, and precious metals. Herein, we report a modified exsolution approach for co-exsolving active oxides and metal nanoparticles from a titanate perovskite, La0.8Ce0.1Ni0.4Ti0.6O3-δ (LCeNT). We highlight strained facet-specific CeO2 cubes can be grown on the support after an air-annealing process with their morphology tunable by varying annealing temperature, whilst exsolution of Ni nanoparticles form subsequently following chemical/electrical reduction. An electrolyte-supported SOFC utilizing CeO2-Ni@LCeNT anode achieves maximum power density of 642 mW cm−2 at 900 ℃ in H2 (∼3% H2O). Exceptional robustness of the heterostructure is illustrated after running the cell in CH4 (∼3% H2O) for 20 h. Overall, this work demonstrates an intriguing pathway to constructing stable and active ceria-metal/titanate heterostructure for energy applications.