Evidence and Model for Strain-Driven Release of Metal Nanocatalysts from Perovskites during Exsolution
Year: 2015
Type: article
Abstract: The evolution of the surface morphology during exsolution of Ni from the perovskite La0.4Sr0.4Ti0.97Ni0.03O3-δ under reducing conditions was determined using atomic force microscopy. The exsolution process was found to initially induce the formation of a 20-30 nm deep pit on the oxide surface followed by the emergence of a Ni particle at the bottom of the pit. Continued emergence of the particle results in it nearly filling the pit, producing a unique structure in which the Ni particle is socketed into the oxide surface. We also show that this morphological evolution can be explained using a simple energy-based model that accounts for the interplay between the surface free energy and the strain energy induced by the included metal nucleate. The unique socketed structure results in strong anchorage between the exsolved particles and the oxide host lattice, which imparts both high thermal stability and unique catalytic activity.
Institutions: University of Pennsylvania, University of St Andrews
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: G1848586159, G3625113730, G3673698839, Materials World Network: Tailoring Electrocatalytic Materials by Controlled Surface Exsolution, G4543966706, G522909762, Materials World Network: Tailoring Electrocatalytic Materials by Controlled Surface Exsolution, G7294309557, G8035652566, Multiscale Modeling of Compositional Stresses in Nonstoichiometric Oxides
OpenAlex ID: W2465806986