【摘要】 <正> 程序升温脱附(TPD)技术在固体表面化学和催化等研究领域中已得到广泛的应用.但由于缺乏有力的理论处理手段,对TPD谱图所提供的信息利用率不高,甚至仍在运用某些错误的处理方法.为此,作者曾对一级脱附反应TPD谱图作过理论分析.本文进一步对二级脱附反应(均匀表面、无再吸附过程)TPD谱图作理论分析.更多还原

【Abstract】 For TPD spectrogram of 2nd-order desorption kinetics, theoretical calculations show that there exist three kinds of relationships among Ed, the activation energy of desorption, k0, the pre-exponential factor, b, the programmed heating rate, and Tm the peak maximum temperature. They are as follows: (see Figs. 2 - 4)(1) Tm increases with the lowering of A[A = ln(k0/b)], while Ed is kept constant;(2) Tm is almost linearly in proportion to Ea, while A is kept constant;(3) A is almost linearly in proportion to Ed, while Tm is kept constant.An equation which represents the relationship between A and Ed at the temperature range of 300 - 1000K is presented as follows:Constants αand β are dependent on Tm and can be found from Fig. 5.The spec’trogram superposition method (SSM) has been used to treat a. spectrum in ref. [3]. The result obtained and the results after refs. [2,3) coincide with each other. That proves the SSM is also suitable to determine Ed and k0 for TPD spectrogram of 2nd-order desorption kinetics with no re-adsorption.更多还原