CeIV

CeIV is shorthand for cerium in the +4 oxidation state, denoted Ce4+ or Ce(IV). In many compounds cerium exists predominantly as Ce4+, particularly in solid oxides and in cerium(IV) salts.

In aqueous solution Ce4+ is a strong oxidant and forms various complexes depending on pH and ligands. Standard potentials for the Ce4+/Ce3+ couple vary with environment but are around +1.6 V in strongly acidic media; the exact value is ligand- and counterion-dependent. Ce4+ is reduced to Ce3+ as it oxidizes substrates.

To stabilize Ce4+ in solution, ligands such as nitrate, sulfate, or fluoride are used, with cerium(IV) ammonium nitrate (CAN) being one of the most common oxidants in organic synthesis. CeO2, ceria, is the most common solid Ce4+ material and features a fluorite-type lattice that can accommodate oxygen vacancies, giving mixed Ce4+/Ce3+ states that underpin its catalytic properties.

Applications include oxidation of alcohols and other organic substrates, oxidation of pollutants in water treatment, and use as polishing powder for glass and optics. In catalysis, the redox cycling between Ce4+ and Ce3+ supports turnover in oxidation reactions and in solid oxide fuel cells.

Safety and handling follow standard oxidant guidelines; avoid contact with incompatible materials and dispose of Ce4+-containing waste per regulations. See also cerium, cerium oxide, ceric ammonium nitrate, cerium salts.