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

• Published in: Journal of catalysis 2013-04, Vol.300, p.225-234
• Main Authors: Xu, Jing, Deng, Ya-Qing, Luo, Yan, Mao, Wei, Yang, Xue-Jing, Han, Yi-Fan
• Format: Article
• Language: English
• Subjects: adsorption; carbon monoxide; Catalysis; Chemistry; CO oxidation; desorption; Exact sciences and technology; General and physical chemistry; Kinetics; Manganese oxides; nanocrystals; Operando; oxidation; oxygen; phase transition; Raman spectroscopy; temperature; Temperature-programmed surface reaction; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; α-Mn2O3 nanocrystals
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2013.01.010

Kinetics with the combination of operando and in situ Raman spectroscopy is used to study the mechanism of CO oxidation over on α-Mn2O3 nanocrystal catalyst. CO oxidation may proceed through the Langmuir–Hinshelwood mechanism (350°C). A reversible phase transformation on an α-Mn2O3 surface can be observed during the adsorption and oxidation of CO. α-Mn2O3 nanocrystals with uniform morphology prepared by calcining a self-assembled Mn3O4 precursor have proved active (ca. 0.14moleculenm-2s-1 at 153°C) toward CO oxidation at low temperatures. The reaction orders with respect to CO and O2 were measured in the temperature range 100–190°C. Operando and in situ Raman spectroscopy are used to determine the near-surface structure of α-Mn2O3 nanocrystals during the adsorption and oxidation of CO for the first time. A surface phase transformation from α-Mn2O3 to MnjOk (1