Thermo-photo degradation of 2-propanol using a composite ceria-titania catalyst: Physico-chemical interpretation from a kinetic model
Thermo-photo degradation of 2-propanol using a composite ceria-titania catalyst: Physico-chemical interpretation from a kinetic model
复制标题
DOI：
10.1016/j.apcatb.2017.11.073
复制
发表时间：
2018-06
期刊：
影响因子：
--
通讯作者：
M. J. Muñoz-Batista;Ana M. Eslava-Castillo;A. Kubacka;M. Fernández-García
中科院分区：
文献类型：
--
作者：
M. J. Muñoz-Batista;Ana M. Eslava-Castillo;A. Kubacka;M. Fernández-García
这项工作描述了一项研究，该研究旨在构建和确定使用基于热光的组合工艺进行2-丙醇气相降解的动力学形式。相对于其母系铈和参比系，观察到铈-二氧化钛复合体系具有优异的催化性能。采用热光实验、平行光实验和单独热实验来解释催化行为。动力学实验采用无内外质热传递的连续流反应器进行，采用Box-Behnken公式设计。建立了热光降解过程的动力学表达式，明确地考虑了光子吸收对反应速率的影响，得到了具有不同物理化学性质的两组分的数学公式。这一事实被用来确定一个拟合程序，使用两个步骤（关于温度、光照强度、氧气、水和/或2-丙醇浓度的两个分离的实验数据集），分别有四个和三个参数。通过对这两个独立实验数据的拟合，验证了动力学形式，与模型预测结果吻合较好。来自动力学模型的参数可以解释氧化铈-二氧化钛催化剂的催化性能，分别量化其在光子和热组分中的增强性能（相对于其母体系统）。该程序适用于各种热光过程，以有助于了解其物理根源。
This work describes a study carried out to construct and determine a kinetic formalism for the gas-phase degradation of 2-propanol using a combined thermo-photo based process. Outstanding catalytic performance was observed for a composite ceria-titania system with respect its parent ceria and titania reference systems. Thermo-photo as well as parallel photo- and thermal-alone experiments were carried out to interpret catalytic behavior. The kinetic experiments were conducted using a continuous flow reactor free of internal and external mass-heat transfer and designed using a Box-Behnken formalism. The kinetic expression developed for the thermo-photo degradation process explicitly includes the effect of the photon absorption in the reaction rate and leads to a mathematical formula with two components having different physico-chemical nature. This fact is used to settle down a fitting procedure using two steps (two separated experimental sets of data concerning temperature, light intensity, oxygen, water and/or 2-propanol concentrations) with, respectively, four and three parameters. The kinetic formalism was validated by fitting the experimental data from these two independent experiments, rendering a good agreement with the model predictions. The parameters coming from the kinetic modelling allow an interpretation of the catalytic properties of the ceria-titania catalyst, quantifying separately its enhanced performance (with respect to its parent systems) in the photonic and thermal components for the process. The procedure is applicable to a wide variety of thermo-photo processes in order to contribute to the understanding of their physical roots.