Effect of metal-doping (Me = Fe, Ce, Sn) on phase composition, structural peculiarities, and CO oxidation catalytic activity of cryptomelane-type MnO2

Manganese oxides attract considerable attention as redox catalysts for abatement of environmental pollutants due to their relatively high activity and low costs contrary noble metal catalysts. The present work is focused on the effect cryptomelane-type MnO2 catalyst modification with Fe3+, Ce3+/Ce4+, Sn4+ phase composition, structural peculiarities, catalytic in CO oxidation. samples are investigated by XRD, Raman spectroscopy, XPS, XRF, comprehensive HRTEM, being studied under model dry conditions simulated real exhaust comprising CO, O2, water balanced inert. Mn4+ substitution cryptomelane structure Men+ revealed result its monoclinic distortion, Sn- Fe-doped formation accompanied SnO2 Fe1−xMnxO3/Fe1+xMn2−xO4, respectively. For Ce-doped samples, K+ presence tunnels essential stabilize nanorod morphology. stabilized only Cen+ cations collapsed during sample calcination form Mn2−xCexO3 Mn3−xCexO4, while Ce content does not favor MnO2. composites based Me-doped α-MnO2, especially those doped Ce, shown be promising candidates develop effective oxide-based