Abstract
X-ray diffractometry and UV-Vis diffuse reflectance spectroscopy revealed that fluorite-structured CeO 2 crystallites (mean size 22.3 nm) are dispersed on silica surfaces (CeSi) into microcrystallites (11.2-8.1 nm) and dispersed further on alumina surfaces (CeAl) into nanocrystallites (< 8.5 nm) and CeO x monolayers. Consequently, IR spectroscopy of adsorbed pyridine found Lewis acid sites to be far more strengthened on CeAl. Bronsted acid sites (proton-donors) were probed exclusively on CeAl. On the other hand, IR spectroscopy of adsorbed deuterated chloroform (CDCl 3) showed the originally moderate Lewis base sites (low-coordinated OH − and O 2−) to be weakened on CeSi, but markedly strengthened on CeAl. Lewis base sites exposed on ceria surfaces assume a strong nucleophilic reactivity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Colloids and Surfaces A: Physicochemical and Engineering Aspects
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.