CH_2(COO)_2Cu·2H_2O热分解的非等温动力学研究

Non-isothermal Kinetic Analysis of Thermal Decomposition of CH_2(COO)_2Cu·2H_2O

羧酸盐特别是草酸盐和乙酸盐的热分解动力学和分解机理研究已有大量报道^[1-5],丙二酸盐热分解过程的报道却并不多。Mohamed等用非等温法研究了二水合丙二酸镍及二水合丙二酸钴的失水和分解过程，比较了其在空气、氢气和氮气中的分解行为^[6、7]。Suzuki等人研究了水合二羧基锰盐在空气中的热分解过程，

The thermal dehydration and decomposition kinetics of CH2（COO）2Cu·2H2O were investigated using the non-isothermal method by thermogravimetry （TG） technique in N2. The iterative iso-conversional methods were applied to calculate the activation energy Ea of dehydration and decomposition, and the most probable mechanism function G（a） was determined by means of the master plots method. The pre-exponential factor A was obtained on the basis of Ea and G（α）. Kinetic parameters （Ea and lnA） of dehydration were given as： Ea=139.79 kJ·mol^-1, In（A/s^-1）= 47.38. The mechanism function of the dehydration was G（α）=[-ln（1-α）]^2/3, and the decomposition of CH2（COO）2Cu proceeds to completion by two distinct reactions. These two reactions overlap in the transition process （0.45〈α〈0.65）. Kinetic parameters （Ea and lnA ）of the first reaction of decomposition were： Ea=201.15 kJ·mol^-1, ln（A/s^-1）=52.29, and the mechanism function was G（α）=[1-α]^-0.37. And in the second reaction G（α）=α＋（1-α）ln（1-α）, Ea=156.74kJ·mol^-1, ln（A/s^-1）=39.58.