Porous Pt-NiO x nanostructures with ultrasmall building blocks and enhanced electrocatalytic activity for the ethanol oxidation reaction.

Oxidized species on surfaces would significantly improve the electrocatalytic activity of Pt-based materials. Constructing three-dimensional porous structures would endow the catalysts with good stability. Here, we report a simple strategy to synthesize porous Pt-NiO x nanostructures composed of ultrasmall (about 3.0 nm) building blocks in an ethanol-water solvent. Structure and component analysis revealed that the as-prepared material consisted of interconnected Pt nanocrystals and amorphous NiO x species. The formation mechanism investigation revealed that the preformed amorphous compounds were vital for the construction of porous structure. In the ethanol oxidation reaction, Pt-NiO x /C exhibited current densities of 0.50 mA cm Pt -2 at 0.45 V ( vs. SCE), which were 16.7 times higher than that of a commercial Pt/C catalyst. Potentiostatic tests showed that Pt-NiO x /C had much higher current and better tolerance towards CO poisoning than the Pt/C catalyst under 0.45 V ( vs. SCE). In addition, the NiO x species on the surface also outperformed an alloyed Ni component in the test. These results indicate that the Pt-NiO x porous nanomaterial is promising for use in direct ethanol fuel cells.