Electro-oxidation of formaldehyde and methanol over hollow porous palladium nanoparticles with enhanced catalytic activity

•Hollow porous Pd nanospheres are fabricated by a simple method.•Porous and partly incomplete shell structure improves the active surface area.•Hollow porous Pd nanospheres exhibit excellent electrocatalytic activity.

Hollow palladium (Pd) nanoparticles with porous shells are simply synthesized via galvanic replacement reaction. The average particle size of hollow Pd nanoparticles is about 15 nm and the thickness of porous shells is about 3 nm. The electrochemical behaviors of these hollow nanoparticles are characterized by cyclic voltammetry (CV). The hollow porous Pd nanoparticles exhibit considerably higher electrocatalytic activity for electrochemical oxidation of formaldehyde and methanol compared to solid Pd nanoparticles, which are promising electrode nano-catalysts for low temperature fuel cells.