The use of solid electrolyte potentiometry in the study of oxygen transferin oxidic catalysts

The cooperation of single phases in a multicomponent oxidic catalyst has be en investigated by combined kinetic and potentiometric (SEP) measurements. Carbon monoxide and an aldehyde have been oxidized on CuMoO4, Mo-V-O-x and a mixture of both solids. Synergetic effects in the mixed catalyst can be e xplained by the flow of oxygen from one single oxide to the other. Its driv ing force, the difference of the oxygen activity between both phases in the mixture, is determined by SEP. The direction of the flow is dependent on t he reaction catalyzed and is inversed in the examples studied. (C) 2000 Els evier Science B.V. All rights reserved.