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

Abstract

Construction of ceria-metal/titanate heterostructurevia exsolution is a promising strategy to improve the catalytic activity oftitanate perovskites and broaden their applications invarious energy conversion scenarios. However, the species exsolved afterreduction are limited to reducible metal cations, such as Ni, Co, Fe, andprecious metals. Herein, we report a modified exsolution approach for co-exsolvingactive 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 thesupport after an air-annealing process with their morphology tunable by varyingannealing temperature, whilst exsolution of Ni nanoparticles form subsequentlyfollowing chemical/electrical reduction. An electrolyte-supported SOFC utilizingCeO2-Ni@LCeNT anode achieves maximum power density of 642 mW cm-2at 900 ℃ in H2 (~3%H2O). Exceptional robustness of the heterostructure is illustrated afterrunning the cell in CH4 (~3% H2O) for 20 hrs. Overall,this work demonstrates an intriguing pathway to constructing stable and activeceria-metal/titanate heterostructure for energy applications.Construction of ceria-metal/titanate heterostructurevia exsolution is a promising strategy to improve the catalytic activity oftitanate perovskites and broaden their applications invarious energy conversion scenarios. However, the species exsolved afterreduction are limited to reducible metal cations, such as Ni, Co, Fe, andprecious metals. Herein, we report a modified exsolution approach for co-exsolvingactive 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 thesupport after an air-annealing process with their morphology tunable by varyingannealing temperature, whilst exsolution of Ni nanoparticles form subsequentlyfollowing chemical/electrical reduction. An electrolyte-supported SOFC utilizingCeO2-Ni@LCeNT anode achieves maximum power density of 642 mW cm-2at 900 ℃ in H2 (~3%H2O). Exceptional robustness of the heterostructure is illustrated afterrunning the cell in CH4 (~3% H2O) for 20 hrs. Overall,this work demonstrates an intriguing pathway to constructing stable and activeceria-metal/titanate heterostructure for energy applications.