Abstract
The detection with ESR of radicals formed upon low temperature oxygen adsorption has been used to study the modifications introduced in the surface of CeO2 by pretreatments with nitric and hydrochloric acids. On untreated CeO2, O2 adsorption originated several types of O−2 species if the sample was previously outgassed at Tv ⩾ 473 K. The HNO3-treated sample did not show signifi signals for Tv ⩽ 573 K; for Tv ⩾ 673 K the spectra were similar to those obtained for untreated CeO2. The HCl-treated sample showed the formation of O2− interacting with Cl− for Tv ⩾ 473 K and subsequently of O−; this indicates the existence of centers, associated to chloride ions, able to activate O2 and dissociate it to give stable O−. These centers are probably present in most M/CeO2 catalysts prepared using metal chloride salts.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
