The electrochemical properties of CeCl3, dissolved in LiCI-KCI eutectic melt, were investigated by electrochemical techniques, such as cyclic voltammetry and square wave voltammetry on Mo electrode. It was shown that...The electrochemical properties of CeCl3, dissolved in LiCI-KCI eutectic melt, were investigated by electrochemical techniques, such as cyclic voltammetry and square wave voltammetry on Mo electrode. It was shown that Ce（Ⅲ） is reduced to Ce（0） based on a three-step mechanism. In a temperature range of 833-923 K, the diffusion coefficient of Ce（Ⅲ） is lgDceoH）=-2.49-1704/T determined by means of the Berzins-Delahay equation with two different expressions under reversible and irreversible conditions. The apparent standard potential of a Ce（Ⅲ）/Ce（0） redox system is ECE^3＋0^＊/Ce^0 =3.551＋0.0006132T（K） vs. Cl2/Cl^-. Some thermochemical properties of CeCl3 solutions were also derived from the electrochemical measurements, such as the enthalpy, entropy, Gibbs free energies and the activity coefficients of Ce（Ⅲ）. The Gibbs free energy of a dilute solution of CeCl3 in this system was determined to be △G^0CeCl3/（kJ·mol^-1）=-1027.9＋0.178T（K） And the activity coefficients, γCeCl3 , range between （7.78-9.14）×10^-3. Furthermore, the standard rate constant of kinetic reaction was calculated to be （4.94-9.72）× 10^-3 cmZ/s and the reaction was regarded as a quasi-reversible reaction under the present experimental conditions at 833 K.展开更多
The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF...The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF) Morse oscillator (MO) potential on unimolecular reaction. We shall use the systematic theoretical approach, YL method, proposed by Yao and Lin (YAO L, et. al. J Phys Chem A, 2007, 111(29): 6722-6729), which can evaluate anharmonic effects on the rate constants based on the transition state theory. In treating the anharmonic effect with the Morse oscillator potential on unimolecular reactions under collision-free conditions by using the RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the in-verse Laplace transformation of the partition functions was used to obtain the total amount of state and density of state by using the first-order and the second-order approximations of the saddle-point method. To demonstrate the anharmonic effect of the SBF Morse model, we choose some model systems and a real reaction as examples.展开更多
基金Supported by the High Technology Research and Development Program of China（No.2011AA03A409）, the National Natural Science Foundation of China（Nos.51104050, 91326113, 21271054, 21173060）, the China Postdoctoral Science Foundation（No.20110491029）, the Heilongjiang Postdoctoral Fund, China（No.LBH-Z10208）, the Heilongjiang Educational Commission Foundation, China（No.12513045）, the Fundamental Research Funds for the Central Universities, China（No.HEUCF141502）, the Project of the Scientific Technology Bureau of Harbin, China（No.2012RFQXS 102） and the Basic Research Foundation of Harbin Engineering University, China（No.HEUFT08031）.
文摘The electrochemical properties of CeCl3, dissolved in LiCI-KCI eutectic melt, were investigated by electrochemical techniques, such as cyclic voltammetry and square wave voltammetry on Mo electrode. It was shown that Ce（Ⅲ） is reduced to Ce（0） based on a three-step mechanism. In a temperature range of 833-923 K, the diffusion coefficient of Ce（Ⅲ） is lgDceoH）=-2.49-1704/T determined by means of the Berzins-Delahay equation with two different expressions under reversible and irreversible conditions. The apparent standard potential of a Ce（Ⅲ）/Ce（0） redox system is ECE^3＋0^＊/Ce^0 =3.551＋0.0006132T（K） vs. Cl2/Cl^-. Some thermochemical properties of CeCl3 solutions were also derived from the electrochemical measurements, such as the enthalpy, entropy, Gibbs free energies and the activity coefficients of Ce（Ⅲ）. The Gibbs free energy of a dilute solution of CeCl3 in this system was determined to be △G^0CeCl3/（kJ·mol^-1）=-1027.9＋0.178T（K） And the activity coefficients, γCeCl3 , range between （7.78-9.14）×10^-3. Furthermore, the standard rate constant of kinetic reaction was calculated to be （4.94-9.72）× 10^-3 cmZ/s and the reaction was regarded as a quasi-reversible reaction under the present experimental conditions at 833 K.
基金Supported by the National Natural Science Foundation of China (Grant No. 10704012)NSC (Taiwan), Academia Sinica, and the Natural Science Foundation of Liaoning Province (Grant No. 2006Z064)
文摘The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF) Morse oscillator (MO) potential on unimolecular reaction. We shall use the systematic theoretical approach, YL method, proposed by Yao and Lin (YAO L, et. al. J Phys Chem A, 2007, 111(29): 6722-6729), which can evaluate anharmonic effects on the rate constants based on the transition state theory. In treating the anharmonic effect with the Morse oscillator potential on unimolecular reactions under collision-free conditions by using the RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the in-verse Laplace transformation of the partition functions was used to obtain the total amount of state and density of state by using the first-order and the second-order approximations of the saddle-point method. To demonstrate the anharmonic effect of the SBF Morse model, we choose some model systems and a real reaction as examples.
