OXIDATION OF CARBON-MONOXIDE OVER BARIUM CUPRATE CATALYSTS

Catalytic activities of BaCuO2, Ba2Cu3O5 and CuO for CO oxidation were investigated. At 250 ° C, BaCuO2 was found to be about 7 times more active than CuO, while Ba2Cu3O5 was found to be only slightly more active than CuO. This result also demonstrates that expensive rare earth elements such as La and Y are not necessary for a cuprate to have good activity for CO oxidation. After sintering at 940 ° C in air, the conversion substantially decreased for CuO. At steady state, both barium cuprates exhibited higher activity than in the fresh state. Based on the absence of significant changes in the XRD spectra, the change in catalytic activity is attributed to changes at the surface and possibly slight reduction of Cu2+. Reaction orders of CO were found to be 1.2 and 0.3, and reaction orders of O2 were found to be 0 and 0.3 for BaCuO2 and Ba2Cu3O5, respectively. © 1990 J.C. Baltzer A.G. Scientific Publishing Company.