最小二乘法计算苯、噻吩和正辛烷在NaY上程序升温脱附活化能

采用程序升温脱附(TPD)技术测定了苯、噻吩和正辛烷在NaY上以不同升温速率升温时的TPD谱图. 利用TPD谱图的峰形和其微分曲线判断了程序升温脱附过程中的脱附级数. 提出了一种利用最小二乘法计算吸附剂/催化剂的脱附活化能及其动力学参数的方法. 以这些TPD谱图为基础, 分别采用传统TPD计算模型、最小二乘法以及一阶微分曲线法计算了苯、噻吩和正辛烷在NaY上的脱附活化能和动力学参数. 结果表明, 最小二乘法对在不同线性升温速率时的程序升温脱附活化能的计算结果是一致的.

Activation Energy of Temperature Programmed Desorption Calculated Using Least-Squares Method for Benzene, Thiophene and Octane on NaY

Temperature programmed desorption (TPD) spectra of benzene, thiophene, and octane on NaYat different heating rates were measured and the order of desorption for the TPD was estimated by the shape of TPD spectra and their characteristic differential curves. A new TPD model using least-squares method was proposed, by which the desorption activation energies, as well as the kinetic parameters of the systems, could be calculated. Based on these experimental spectra, desorption activation energies of benzene, thiophene, and octane on NaY were calculated by a traditional model, the least-squares method, and the first differential curve of the TPD model. The results show that the desorption activation energies at different heating rates calculated by the least-squares method agree well with each other.