Temperature oscillations characterized by an overall activation energy

Temperature oscillations obtained during the heterogeneous catalytic oxidat ion of ethanol on Pd-Al2O3 in a dynamic calorimeter were characterized by a n overall activation energy. This parameter was determined by a non-isother mal kinetic method using the minimum and maximum values of the oscillations temperature. Using the bifurcation diagram with the oxygen as a bifurcatio n parameter an E value between 27.6 and 28.2 kJ mol(-1) was obtained. With ethanol as bifurcation parameter the E values lies between 28.1 and 31.1 kJ mol(-1) for 3.5 to 4.0 vol% ethanol and between 25.8 and 27.6 kJ mol(-1) f or 4.0 to 4.7 vol% ethanol. These results have been discussed.