Hydrotalcite-derived Co-containing mixed metal oxide catalysts for methanol incineration Role of cobalt content, Mg/Al ratio and calcination temperature

作者：Basag Sylwia; Kovanda Frantiek; Piwowarska Zofia; Kowalczyk Andrzej; Pamin Katarzyna; Chmielarz Lucjan^*

来源：Journal of Thermal Analysis and Calorimetry, 2017, 129(3): 1301-1311.

DOI：10.1007/s10973-017-6348-7

• Hydrotalcite-like materials
• Co-Mg-Al mixed oxide catalysts
• Spinel formation
• VOC total oxidation
• Methanol incineration

The Co-Mg-Al mixed metal oxides were prepared by calcination of co-precipitated hydrotalcite-like precursors at various temperatures (600-800 A degrees C), characterised with respect to chemical (AAS) and phase (XRD) composition, textural parameters (BET), form and aggregation of cobalt species (UV-vis-DRS) and their redox properties (H-2-TPR, cyclic voltammetry). Moreover, the process of thermal decomposition of hydrotalcite-like materials to mixed metal oxide systems was studied by thermogravimetric method combined with the analysis of gaseous decomposition products by mass spectrometry. Calcined hydrotalcite-like materials were tested as catalysts for methanol incineration. Catalytic performance of the oxides depended on cobalt content, Mg/Al ratio and calcination temperature. The catalysts with lower cobalt content, higher Mg/Al ratio and calcined at lower temperatures (600 or 700 A degrees C) were less effective in the process of methanol incineration. In a series of the studied catalysts, the best results, with respect to high catalytic activity and selectivity to CO2, were obtained for the mixed oxide with Co:Mg:Al molar ratio of 10:57:33 calcined at 800 A degrees C. High activity of this catalyst was likely connected with the presence of a Co-Mg-Al spinel-type phases, containing easy reducible Co3+ cations, formed during high-temperature treatment of the hydrotalcite-like precursor.

• 出版日期2017-9