, The decarboxylation of D152 occurred primarily in the range of 335–500 C. The peaks of CO2 and CO were at 440 C and 470 C respectively. By comparing the curves of thermogravimetric analysis (Fig. 2) and differential ther- mal analysis (Fig. 3) of preoxygenated Ni–Ca/D152 and D152, it can be concluded that the pyrolysis of D152 was significantly accelerated by the catalysis of nickel and calcium