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607719 
Journal Article 
Fenton-Like Reaction Catalyzed by the Rare Earth Inner Transition Metal Cerium 
Heckert, EG; Seal, S; Self, WT 
2008 
1 
Environmental Science & Technology
ISSN: 0013-936X
EISSN: 1520-5851 
42 
13 
5014-5019 
English 
18678042 
WOS:000257220600068 
Cerium (Ce) is a rare earth metal that is not known to have any biological role. Cerium oxide materials of several sizes and shapes have been developed in recent years as a scaffold for catalysts. Indeed even cerium oxide nanoparticles themselves have displayed catalytic activities and antioxidant properties in tissue culture and animal models. Because of ceria's ability to cycle between the +3 and +4 states at oxygen vacancy sites, we investigated whether cerium metal would catalyze a Fenton-like reaction with hydrogen peroxide. Indeed, cerium chloride did exhibit radical production in the presence of hydrogen peroxide, as assessed by relaxation of supercoiled plasmid DNA. Radical production in this reaction was also followed by production of radical cation of 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). Radical scavengers and spin traps were capable of competing with ABTS for radicals produced in this cerium dependent Fenton-like reaction. Electron paramagnetic resonance experiments reveal both hydroxyl radical and superoxide anion in a reaction containing cerium and hydrogen peroxide. Based on these results we propose that cerium is capable of redox-cycling with peroxide to generate damaging oxygen radicals. [ABSTRACT FROM AUTHOR] Copyright of Environmental Science & Technology is the property of American Chemical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts) 
CERIUM oxides; CATALYSTS; RESEARCH; CHLORIDES; RADICALS (Chemistry); ANIONS; CATIONS