CATALYTIC-OXIDATION OF CARBON-MONOXIDE OVER SUPERCONDUCTING LA2-XSRXCUO4-DELTA-SYSTEMS BETWEEN 373-523-K

The catalytic oxidation of carbon monoxide on superconducting La2-xSrxCuO4-δ systems has been studied in the temperature range 373 to 573 K. These solid oxide solutions are found to show high catalytic activity for oxidation (carbon monoxide oxidation) which is comparable to that of a highly dispersed 0.5% Pt/alumina fume abatement catalyst. The kinetics of CO oxidation on these solid oxide solutions conforms to the same Langmuir-Hinshelwood model as that of the Pt/alumina catalyst. The catalytic activity which was studied as a function of Sr concentration (x) in these solid oxide solutions shows a "volcano" behavior with a maximum activity at x = 0.4. The variation of catalytic activity is compared and found to be concomitant with that of the variation of the electrical conductivity, lattice parameter, and oxygen vacancy concentration on the K2NiF4-type La2-xSrxCuO4-δ lattice and the thermodynamic activity of SrO. © 1991.