ATR-FTIR spectrokinetic analysis of the CO adsorption and oxidation at water/platinum interface
ATR-FTIR spectrokinetic analysis of the CO adsorption and oxidation at water/platinum interface
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DOI：
10.1016/j.cattod.2016.03.042
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发表时间：
2017-04-01
期刊：
影响因子：
5.3
通讯作者：
Collins, Sebastian E.
中科院分区：
文献类型：
--
作者：
Aguirre, Alejo;Berli, Claudio L. A.;Collins, Sebastian E.
衰减全反射红外（ATR-IR）光谱是研究液体（反应性）/固体（催化剂）体系中反应途径的有力工具。催化剂通常作为粉末层或作为膜（例如金属膜）沉积在内反射元件（IRE）上，并且它们暴露于液相反应物。为了获得本征反应速率的定量信息，必须评估ATR流通池的化学工程方面。特别地，必须表征ATR池中的质量传递。我们在这里提出了一个分析的质量传递从流动的解决方案的ATR晶体的表面，在那里的催化剂沉积。根据无量纲Peclet数（Pe）和舍伍德数（Sh）以及Thiele模数（phi（cl）），建立了化学控制下的动力学参数的判定标准。采用气相沉积法在ZnSe IRE上沉积Pt薄膜和一层Pt/Al 2 O3多孔催化剂，研究了水相对一氧化碳的吸附和预吸附一氧化碳的氧化。用微动力学模型拟合了线性吸附CO（2048 cm（-1））的实验数据，得到了反应常数。这里报告的结果作为一个实用的指导，以快速确定ATR电池的操作限制与多孔层的催化剂沉积到IRE上。(C)© 2016 Elsevier B. V.版权所有。
Attenuated total reflection infrared (ATR-IR) spectroscopy is a powerful tool to investigate reaction pathways in liquid(reactive)/solid(catalyst) systems. Catalysts are commonly deposited on an internal reflection elements (IRE) as layers of powders or as films (e.g. metal film), and they are exposed to the liquid phase reactants. To obtain quantitative information of intrinsic reaction rates, the chemical engineering aspects of an ATR flow-through cell must be evaluated. Particularly, mass transport in the ATR cell has to be characterized. We present here an analysis of the mass transfer from the flowing solution to the surface of the ATR crystal, where the catalyst is deposited. Criteria to determine kinetic parameters under chemical control were developed on the base of non-dimensional Peclet (Pe) and Sherwood (Sh) numbers, and Thiele modulus (phi(cl)). A Pt thin film deposited on a ZnSe IRE by vapor deposition and a layer of Pt/Al2O3 porous catalyst were used to study the adsorption of carbon monoxide and oxidation of preadsorbed carbon monoxide on aqueous phase. Experimental data of the evolution of the linearly adsorbed CO (2048 cm(-1)) were fitted using a microkinetic model to obtain reaction constants. Results reported here serve as a practical guide to quickly determine the operational limits of an ATR cell with a porous layer of catalyst deposited onto the IRE. (C) 2016 Elsevier B.V. All rights reserved.