Intrinsic kinetics of carbon dioxide degradation of YBa2Cu3O7-x

This paper reports on the intrinsic kinetics, unaffected by diffusional and mass-transfer effects, of the CO2 degradation of superconducting particles that have been determined using a nonisothermal technique. Below 900 degrees C, the carbonization of YBa2Cu3O7-x leads to formation of BaCO3, Y2Cu2O5, CuO, and Cu2O. A further increase in temperature results in formation of BaCuO2 from BaCO3 and CuO. The carbonization rate shows the 1.5th-order dependence on the amount of unreacted YBa2Cu3O7-x for the temperature range of 550 degrees to 815 degrees C. The activation energy of carbonization was determined to be 95.1 kJ · mol-1