Exceptional Low-Temperature CO Oxidation over Noble-Metal-Free Iron-Doped Hollandites: An In-Depth Analysis of the Influence of the Defect Structure on Catalytic Performance

A family of iron-doped manganese-related hollandites, KxMn1−yFeyO2−δ (0 ≤ y ≤ 0.15), with high performance in CO oxidation have been prepared. Among them, the most active catalyst, K0.11Mn0.876Fe0.123O1.80(OH)0.09, is able to oxidize more than 50% of CO at room temperature. Detailed compositional and structural characterization studies, using a wide battery of thermogravimetric, spectroscopic, and diffractometric techniques, both at macroscopic and microscopic levels, have provided essential information about this never-reported behavior, which relates to the oxidation state of manganese. Neut... Mehr ...