Solvothermal preparation of Pd nanostructures under nitrogen and air atmospheres and electrocatalytic activities for the oxidation of methanol

Monodispersed Pd nanoparticles and their porous spherelike aggregates with different lattice parameters were solvothermally prepared under nitrogen and air atmospheres. Here PdCl₂ acted as Pd precursor and hexadecylamine played the roles of solvent, reductant, and surface capping agent. Oxygen existing in air resulted in the change of surface capping agent, which then induced the aggregation of Pd nanoparticles, and the incorporation of oxygen led to the expansion of its lattice parameter to 0.398 nm, whereas the standard lattice parameter in metallic Pd is 0.389 nm. The monodispersed nanoparticles presented better catalytic activity and stability for the oxidation of methanol than the sphere-like Pd aggregates.