1. Effect of manganese promotion on the activity and selectivity of cobalt catalysts for CO preferential oxidation
- Author
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Spyridon Zafeiratos, David Horst Simonne, Walid Baaziz, Michael Haevecker, Mathias Barreau, Dingkai Chen, Valérie Caps, Břetislav Šmíd, Liping Zhong, Detre Teschner, Elisa Borfecchia, Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI), Max Planck Society, Università degli studi di Torino (UNITO), Charles University [Prague] (CU), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), and univOAK, Archive ouverte
- Subjects
inorganic chemicals ,NAP-XPS ,chemistry.chemical_element ,Context (language use) ,02 engineering and technology ,Manganese ,Operando spectroscopy ,COPrOx ,010402 general chemistry ,01 natural sciences ,Hydrogen purifier ,Catalysis ,Mixed oxides ,NEXAFS ,Transition metal ,Methanation ,Reactivity (chemistry) ,Selectivity ,General Environmental Science ,Cobalt oxides ,Manganese oxides ,Process Chemistry and Technology ,[CHIM.CATA] Chemical Sciences/Catalysis ,[CHIM.CATA]Chemical Sciences/Catalysis ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,0210 nano-technology ,Cobalt ,Chimie/Catalyse - Abstract
The preferential oxidation of CO in H2-rich mixtures (COPrOx) is a major catalytic reaction utilized for hydrogen purification. In the exploration of alternatives to noble metals, cobalt-based catalysts appear to be a very promising choice. The activity and stability of cobalt in the COPrOx reaction can be improved by the addition of transition metals and manganese is maybe the most prominent among them. Yet, the arrangement of the two components in the catalytically active state is largely unknown, which hinders in-depth understanding of the manganese promotion effect. Here, we compare pure and Mn-modified cobalt catalysts and correlate their structural and chemical characteristics with their COPrOx performance. The Mn-promoted cobalt catalyst is significantly more active than pure cobalt especially at intermediate reaction temperatures (around 200 °C). The addition of Mn improves the structural stability of the catalyst and helps to maintain higher specific surface areas. Chemical and microstructural analysis using various operando and in situ techniques revealed that Mn promotes CO conversion by partially stabilizing CoO phase during reaction conditions. It is also suggested that at high temperature, Mn suppress CO methanation reaction but promotes H2 oxidation. Apart of the particular interest in COPrOx reaction, in a general context, this work shows how the spatial distribution of the different catalyst components at nanoscopic level, may affect the surface chemistry and consequently control the reactivity.
- Published
- 2021
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