PtCuNi Tetrahedra Catalysts with Tailored Surfaces for Efficient Alcohol Oxidation.

Direct methanol/ethanol alkaline fuel cells (DMAFCs/DEAFCs) represent an attractive mobile power generation technology. The methanol/ethanol oxidation reaction (MOR/EOR) often requires high-performance yet expensive Pt-based catalysts that may be easily poisoned. Herein, we report the development of PtCuNi tetrahedra electrocatalysts with optimized specific activity and mass activity for MOR and EOR. Our synthetic and structural characterizations show that these PtCuNi tetrahedra have Cu-rich core and PtNi-rich shell with tunable surface composition. Electrocatalytic studies demonstrate that Pt56Cu28Ni16 exhibits exceptional MOR and EOR specific activities of 14.0 ± 1.0 mA/cm2 and 11.2 ± 1.0 mA/cm2, respectively and record high mass activity of 7.0 ± 0.5 A/mgPt and 5.6 ± 0.6 A/mgPt, comparing favorably with the best MOR or EOR Pt alloy-based catalysts reported to date. Furthermore, we show that the unique core-shell tetrahedra configuration can also lead to considerably improved durability.