文献类型：期刊文献

英文题名：Operando Raman spectroscopy and kinetic study of low-temperature CO oxidation on an α-Mn2O3 nanocatalyst

作者：Xu, Jing[1];Deng, Ya-Qing[1];Luo, Yan[1];Mao, Wei[1];Yang, Xue-Jing[1];Han, Yi-Fan[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2013

卷号：300

起止页码：225

外文期刊名：JOURNAL OF CATALYSIS

收录：;EI(收录号：20131116123776);WOS:【SCI-EXPANDED(收录号:WOS:000317558000025)】；

基金：The authors are grateful for support from the Chinese Education Ministry 111 project (B08021), the National Science Foundation (21176071, 21106041, 21273070), the Shanghai PuJiang Talent Program (2011/11PJ1402400), the Science and Technology Commission of Shanghai Municipality (11JC1402700), the Innovation Program of Shanghai Municipal Education Commission (11ZZ52, 12ZZ051), the Shanghai Natural Science Foundation (11ZR1408400), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Raman spectroscopy; Operando; Kinetics; CO oxidation; Manganese oxides; alpha-Mn2O3 nanocrystals; Temperature-programmed surface reaction

摘要：alpha-Mn2O3 nanocrystals with uniform morphology prepared by calcining a self-assembled Mn3O4 precursor have proved active (ca. 0.14 molecule nm(-2) s(-1) at 153 degrees C) toward CO oxidation at low temperatures. The reaction orders with respect to CO and O-2 were measured in the temperature range 100-190 degrees C. Operando and in situ Raman spectroscopy are used to determine the near-surface structure of alpha-Mn2O3 nanocrystals during the adsorption and oxidation of CO for the first time. A surface phase transformation from alpha-Mn2O3 to MnjOk (1 < j < 2, 1 < k < 3, and 1 < k/j < 1.5) intermediate species was observed in gaseous CO with the change in temperature. In addition, with the combination of the temperature-programmed desorption of O-2, temperature-programmed surface reaction of CO oxidation, operando Raman spectra, and kinetics parameters, we conclude that the oxidation of CO may proceed through the Langmuir-Hinshelwood mechanism (<200 degrees C) to the Mars van Krevelen mechanism (>350 degrees C) with increasing reaction temperature. In particular, the adsorbed oxygen is deduced to be responsible for CO oxidation at lower temperatures. (C) 2013 Elsevier Inc. All rights reserved.