Correlation of Bulk and Surface Thermodynamics of Some Transition Metal Oxides; Application to Exhaust Gas Catalysts

Information on the stability of chemisorbed oxygen on oxidic surfaces, especially in relation to the stability of bulk oxides, is rather scarce. Therefore, an empirical model based on localized interactions has been formulated in circumventing the problem of the nature of the bond. From it, the enthalpy of formation of a transition metal oxide can be predicted once the structure of that oxide and both the structure and enthalpy of formation of another oxide of the same metal are known. Also, the enthalpy of formation of mixed oxides can be predicted once their structure is known and data on the corresponding monometallic oxides have been evaluated. Finally, the model has been extended towards oxidic surfaces in order to predict the stability of adsorbed oxygen.