Manganese dioxide polymorphs or octahedral molecular sieves (OMS) of manganese are relatively cheap and promising alternatives to noble metals in DMFC and active catalysts of organic compounds oxidation. Doped OMS samples were electrodeposited on a Pt anode in 0.2M HF and 0.7M MnSO4 containing additives MOH (Li, Na, K, NH4+) or MSO4 (Fe2+, Co2+) at a current density i = 0.1�10 A�dm-2. Porosity was measured by a Quantachrome ASAP 2000M Micrometric Sorptometer. Film electrodes were used to study electrocatalytic properties in 2.5M H2SO4, 1.0M C2H5OH electrolyte. Figure 1 shows the micropores distribution in some electrodeposited samples. Alkali-metal dopants (curves 2-3) are the templates of OMS-2 channels with tunnel size 0.46 nm unlike transition metal ions (Co2+, curve 4). Undoped manganese dioxide also contains significant number of OMS-2 tunnels. Figure 2 shows Tafel plot ?-logi of anode process on stainless steel 1Cr18Ni10?i grade (1), Pt (2), undoped and doped by Na+ MnO2.(3-4, respectively).

Electrocatalysis of ethanol oxidation on doped octahedral molecular sieves of manganese

239th National Meeting (2010)

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