Surface structure and redox chemistry of ceria-containing automotive catalytic systems

A summary is given of recent work done at the authors' laboratory, using se veral spectroscopies, molecular modeling and catalytic activity tests, to s tudy the surface reactivity of ceria-containing high surface area solids us eful for automotive exhaust depollution catalysis. Issues addressed include the influence of the basicity of the cerium ion ligand environment on its ability for activation of O-2 at the material surface, and its modification by supporting on alumina or doping with Cl- or other anions; the tendency to grouping of oxygen vacancies at the CeO2 (1 1 1) surface, the higher eas e for formation of surface reduced centers in mixed (Zr,Ce) oxides; and the effect of electronic transfer and other chemical interactions induced by c eria on the redox reactivity of transition metal-containing catalysts.