Metal Nanoparticle Exsolution on a Perovskite Stannate Support with High Electrical Conductivity

Abstract

In situ exsolution of metal nanoparticles (NPs) is emerging as an alternative technique to deliver thermally stable and evenly dispersed metal NPs, which exhibit excellent adhesion with conducting perovskite oxide supports. Here we provide the first demonstration that Ni metal NPs with high areal density (similar to 175 mu m(-2)) and fine size (similar to 38.65 nm) are exsolved from an Asite-deficient perovskite stannate support (La0.2Ba0.7Sn0.9Ni0.1O3-delta(LBSNO)). The NPs are strongly anchored and impart coking resistance, and the Ni-exsolved stannates show exceptionally high electrical conductivity (similar to 700 S.cm(-1)). The excellent conductivity is attributed to conduction between delocalized Sn Ss orbitals along with structural improvement toward ABO(3) stoichiometry in the stannate support. We also reveal that experimental conditions with strong interaction must be optimized to obtain Ni exsolution without degrading the perovskite stannate framework. Our finding suggests a unique process to induce the formation of metal NPs embedded in stannate with excellent electrical properties.