Radiochemical synthesis of a carbon-supported Pt–SnO2 bicomponent nanostructure exhibiting enhanced catalysis of ethanol oxidation

• Ethanol oxidation catalysis was enhanced by Sn-addition, far less than ever reported.
• Pt–SnO2 contact is crucial to the catalysis enhancement, alloying of Sn is not necessary.
• Nano-scaled intimate contact between Pt and SnO2 was directly observed.

Carbon-supported Pt–SnO2 electrocatalysts with various Sn/Pt molar ratios were prepared by an electron beam irradiation method. These catalysts were composed of metallic Pt particles approximately 5 nm in diameter together with low crystalline SnO2. The contact between the Pt and SnO2 in these materials varied with the amount of dissolved oxygen in the precursor solutions and it was determined that intimate contact between the Pt and SnO2 significantly enhanced the catalytic activity of these materials during the ethanol oxidation reaction. The mechanism by which the contact varies is discussed based on the radiochemical reduction process.