Kinetic study and the effect of particle size on low temperature CO oxidation over Pt/TiO2 catalysts
Kinetic study and the effect of particle size on low temperature CO oxidation over Pt/TiO2 catalysts
复制标题
Pt/TiO2 催化剂上低温 CO 氧化的动力学研究及粒径影响
DOI：
10.1016/j.apcatb.2013.05.068
复制
发表时间：
2013-10-01
影响因子：
22.1
通讯作者：
Lu, Ji-Qing
中科院分区：
文献类型：
--
作者：
Li, Na;Chen, Qiu-Yan;Lu, Ji-Qing
制备了一系列不同铂颗粒大小的铂/二氧化钛催化剂，并对其低温CO氧化性能进行了测试。考察了铂颗粒大小对反应的影响。结果表明，基于铂分散度的循环频率随铂颗粒尺寸的增大呈下降趋势，与d(-0.86)成正比。然而，位于铂-二氧化钛界面外围的铂原子的翻转频率在40℃时保持不变，这意味着这些外围的铂原子是活性中心。对催化剂上的反应途径进行了动力学研究。在40℃时，动力学方程为r=1.98×10(-7)(PCOPO20.19)-P-0.29。根据动力学结果，提出了该反应的基本步骤：CO在铂原子上的化学吸附和O-2在二氧化钛上的化学吸附，以及这两种物种在铂-二氧化钛界面上的反应。(C)2013爱思唯尔B.V.保留所有权利。
A series of Pt/TiO2 catalysts with various Pt particle sizes were prepared and tested for low temperature CO oxidation. The effect of Pt particle sizes on the reaction was investigated. It was found that turnover frequencies based on Pt dispersion varied as declined with increasing Pt particle size as a function of d(-0.86). However, turnover frequency based on Pt atoms located on the periphery of Pt-TiO2 interface remained constant at 40 degrees C, implying that these periphery Pt atoms were the active sites. Kinetic study was conducted to investigate reaction pathway on the catalyst. The derived power rate law expression was r=1.98 x 10(-7) (PCOPO20.19)-P-0.29 at 40 degrees C. Based on the kinetic results, elementary steps of this reaction were proposed, which involved chemisorption of CO on Pt atoms and chemisorption of O-2 on TiO2 and a reaction of these two species at the Pt-TiO2 interface. (c) 2013 Elsevier B.V. All rights reserved.