Metal particles supported on oxide surfaces are used as catalysts for a wide variety of processes in the chemical and energy conversion industries. For catalytic applications, metal particles are generally formed on an oxide support by physical or chemical deposition, or less commonly by exsolution from it. Although fundamentally different, both methods might be assumed to produce morphologically and functionally similar particles. Here we show that unlike nickel particles deposited on perovskite oxides, exsolved analogues are socketed into the parent perovskite, leading to enhanced stability and a significant decrease in the propensity for hydrocarbon coking, indicative of a stronger metal–oxide interface. In addition, we reveal key surface effects and defect interactions critical for future design of exsolution-based perovskite materials for catalytic and other functionalities. This study provides a new dimension for tailoring particle–substrate interactions in the context of increasing interest for emergent interfacial phenomena.

The electrical-insulation degradation of $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$ is now of growing interest as the $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$ -based dielectric layers of multilayer ceramic capacitors are getting thinner to submicron thicknesses. The degradation is understood to be due to the electrotransport of oxygen vacancies and may be monitored by the colors emanating from the cathode and/or anode. In the case of single crystal $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$ , a brown color emanates from the anode and a blue color from the cathode. We will experimentally review the generation of the colors in $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$ in electric fields, and discuss their origins and kinetics of color front migration. From the latter the oxygen vacancy mobility against temperature in the range of $150–500°\mathrm{C}$ is subsequently determined and compared with all the literature data that have normally been estimated by other means at elevated temperatures.