Fenton-like reaction catalyzed by the rare earth inner transition metal cerium

    Authors

    E. G. Heckert; S. Seal;W. T. Self

    Comments

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    Abbreviated Journal Title

    Environ. Sci. Technol.

    Keywords

    OXIDE NANOPARTICLES; SUPEROXIDE GENERATION; QUANTITATIVE MEASUREMENT; NANOCRYSTALLINE CERIA; HYDROGEN-PEROXIDE; PULSE-RADIOLYSIS; OXIDATIVE; STRESS; DNA-DAMAGE; CELLS; MECHANISM; Engineering, Environmental; Environmental Sciences

    Abstract

    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.

    Journal Title

    Environmental Science & Technology

    Volume

    42

    Issue/Number

    13

    Publication Date

    1-1-2008

    Document Type

    Article

    Language

    English

    First Page

    5014

    Last Page

    5019

    WOS Identifier

    WOS:000257220600068

    ISSN

    0013-936X

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