Salt-templated platinum–palladium porous macrobeam synthesis

Here we present the synthesis of porous platinum–palladium macrobeams templated from high aspect ratio Magnus’ salt needle derivatives. The combination of [PtCl 4 ] 2− and/or [PdCl 4 ] 2− with [Pt(NH 3 ) 4 ] 2+ ions results in salt needles ranging from 15 to 300 µm in length. Electrochemical reduction of the salt templates results in porous macrobeams with a square cross-section. Porous side wall texture and elemental composition was controlled with initial platinum to palladium salt ratio. Macrobeam free-standing films exhibited a specific capacitance up to 11.73 F/g and a solvent accessible surface area of 26.6 m 2 /g. These salt-templated porous platinum–palladium macrobeams offer a promising material for fuel cell catalysis.