The effects of thermal treatment on the microstructure of a Pt–Pd/Al2O3 oxidation catalyst and its activity for CO oxidation have been studied. The microstructural analysis was performed by using several high‐resolution electron microscopy techniques such as STEM, FIB/SEM slice & view, SEM and EDX. A combination of these analytic techniques and advanced TEM specimen preparation allowed for three‐dimensional probing at different length scales, avoiding the random character of conventionally crushed powder specimens owing to site specificity. A core–shell distribution of Pt–Pd nanoparticles within the alumina support particles, with enlarged nanoparticles (≈1.5 to 40 nm) present in the shell and small nanoparticles (<1.5 nm) in the core, was revealed in the untreated catalyst. A more uniform spatial distribution developed during thermal treatment at 700 °C or higher with larger nanoparticles forming in the core. Accompanying measurements of the catalytic activity for CO oxidation showed the detrimental effect of sintering of the small nanoparticles on the reaction rate and apparent activation energy of the reaction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.