REDUCTION REACTION OF LANTHANUM-ADDED CERIUM DIOXIDE WITH CARBON-MONOXIDE

The reaction of lanthanum-added cerium dioxide with carbon monoxide was examined by using a CO pulse reaction method and high-temperature X-ray diffraction (XRD). The lanthanum addition enhanced the activity of cerium dioxide for oxidizing carbon monoxide under moderately reducing conditions. Isothermal XRD observation at 500 and 700-degrees-C indicated that the reduction reaction of CeO2 and La-added CeO2 with CO progressed in CO-N2 flowing gas. The kinetics of the reaction CeO2 + x/2CO --> Ce1-x4+Ce(x)3+O2-x/2 + x/2CO2 + x/2V(o) was analysed by Jander's model: [1 - (1 - x)1/3]2 = kt.