Synthesis of Pt-Rare Earth Metal Nanoalloys.

Chemical synthesis of platinum-rare earth metal (Pt-RE) nanoalloys, one of the most active catalysts for the oxygen reduction reaction, has been a formidable challenge, mainly due to the vastly different standard reduction potentials of the two metals and high oxophilicity of the latter. Here we report a universal chemical process to prepare Pt-RE nanoalloys with tunable compositions and particle sizes. Pt and RE metal ions from the most common hydrated metal salts are first atomically embedded into an in situ formed C-N network, yielding a stable compound insensitive to O and HO.

Electrochemical probing into the active sites of graphitic-layer encapsulated iron oxygen reduction reaction electrocatalysts.

The graphitic-layer encapsulated iron-containing nanoparticles (G@Fe) have been proposed as a potential type of active and stable non-precious metal electrocatalysts (NPMCs) for the oxygen reduction reaction (ORR). However, the contribution of the encapsulated components to the ORR activity is still unclear compared with the well-recognized surface coordinated FeN/C structure. Using the strong complexing effect of the iron component with anions, cyanide (CN) in alkaline and thiocyanate (SCN) in acidic media, the metal containing active sites are electrochemically probed.