On the development of kinetic models for solvent-free benzyl alcohol oxidation over a gold-palladium catalyst
On the development of kinetic models for solvent-free benzyl alcohol oxidation over a gold-palladium catalyst
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DOI：
10.1016/j.cej.2017.11.165
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发表时间：
2018-06-15
影响因子：
15.1
通讯作者：
Gavriilidis, Asterios
中科院分区：
文献类型：
--
作者：
Galvanin, Federico;Sankar, Meenakshisundaram;Gavriilidis, Asterios
TiO2 负载的双金属 Au-Pd 纳米粒子在苯甲醇无溶剂转化为苯甲醛时表现出优异的催化活性和对苯甲醛的选择性，其中甲苯是观察到的主要副产物，以及少量的苯甲酸、苯甲酸苄酯和二苄基醚。然而，尽管该反应具有工业相关性以及调整对所需苯甲醛的选择性的重要性，但文献中仅进行了一些尝试对反应动力学进行建模以定量描述该反应系统。本文提出了 Au-Pd 上苯甲醇氧化的动力学模型。该模型假设氢解、歧化和脱氢反应可能同时发生，并且在将模型判别程序应用于微动力学研究开发的许多简化候选模型后，发现该模型令人满意。尽管相对简单，所提出的模型能够表示在搅拌间歇反应器中在不同温度、压力和催化剂质量下进行的实验中观察到的反应物转化率和产物分布。主要发现包括定量评估氢解和歧化途径对苯甲醛生产的影响。在低温下，歧化反应是形成甲苯的主要途径，而在高温下，氢解反应占主导地位。
Bimetallic Au-Pd nanoparticles supported on TiO2 show excellent catalytic activity and selectivity to benzaldehyde in the solvent-free transformation of benzyl alcohol to benzaldehyde, where toluene is the main observed by-product, together with smaller amounts of benzoic acid, benzyl benzoate and dibenzyl ether. However, despite the industrial relevance of this reaction and importance of tuning the selectivity to the desired benzaldehyde, only a few attempts have been made in the literature on modeling the reaction kinetics for a quantitative description of this reaction system. A kinetic model for the oxidation of benzyl alcohol over Au-Pd is proposed in this paper. The model assumes that hydrogenolysis, disproportionation and dehydrogenation reactions may occur in parallel, and it has been found satisfactory after a model discrimination procedure was applied to a number of simplified candidate models developed from microkinetic studies. Despite its relative simplicity, the proposed model is capable of representing the reactant conversion and distribution of products observed in experiments carried out at different temperature, pressure and catalyst mass in a stirred batch reactor. Major findings include the quantitative evaluation of the impact of hydrogenolysis and disproportionation pathways on benzaldehyde production. At low temperature the disproportionation reaction is the dominant route to toluene formation, while hydrogenolysis dominates at high temperature.