Recombination of oxygen atoms on oxide surfaces. Part 3.—Catalytic activities of doped oxides

The recombination of oxygen atoms has been studied on the surfaces of pure and doped Fe2O3, NiO and ZnO at 300°K. Increasing p-typeness achieved by doping with lower valent ions, led in all cases to some increase in the recombination rate. Increasing n-typeness, caused by doping with higher valent ions, also produced an increase in activity relative to that of the pure parent oxide, which was most marked for Cr-doped NiO. A simple electrostatic approach was shown to account qualitatively for these observations.