Insight on Strain Relaxation Effect in Perovskites for High-Temperature Hydrogen Oxidation Reaction

Abstract

The size of in situ exsolved nanoparticles (NPs) significantly affects the electrochemical and electro-catalytic properties of oxide supports. Unfortunately, the instrumental factor affecting the exsolved NP size in poly-crystalline perovskite oxides is still unexplored. Herein, the inherent micro-strain (epsilon) value as an unprecedented factor in controlling the exsolved NP size of Pr0.5Ba0.5-xSrxFe0.85Ni0.15O3-delta (x = 0.3, 0.4, and 0.5) is introduced, wherein smaller NP size is successfully obtained via strain relaxation strategy. The effect of exsolved NP size on the fuel oxidation reaction kinetics at high-temperature regimes is evaluated in-depth by using density functional theory (DFT) calculations. In accordance with the insights provided by DFT calculations, the electro-catalyst featuring the smallest Fe3Ni NP size via strain relaxation strategy demonstrates exceptional electrochemical performance along with robust durability toward high-temperature hydrogen oxidation reaction. This work presents scientific guidance for tailoring the exsolved NP size in perovskites, thereby paving the way for designing rational perovskite electro-catalysts in various energy-related applications. The electro-catalyst (R-PBSFN50 material) featuring the smallest Fe3Ni NP size via strain relaxation strategy in poly-crystalline perovskites demonstrates excellent electrochemical performance (Maximum power density output of 1.28 W cm-2) coupled with robust durability toward hydrogen oxidation reaction at high-temperature regimes. image