Pt1.4Ni(100) Tetrapods with Enhanced Oxygen Reduction Reaction Activity

Precisely tuning structure and selectively exposing active surfaces of Pt-based alloys are critical to improving the utilization of precious Pt and promoting electrocatalytic performance. It is worth noting that (100) facets of Pt alloys are universally recognized as less active towards the oxygen reduction reaction (ORR). Herein, a simple and mild approach is proposed to prepare Pt1.4Ni tetrapods (PtNi-TPs) whose surface is predominantly covered by (100) facets via simultaneously reducing the Ni and Pt precursors. In spite of the large proportion of exposed (100) facets, the Pt1.4Ni tetrapods show superior electrocatalytic activity, demonstrating an enhanced ORR mass activity of 1.23 A mg−1Pt and specific activity of 2.01 mA cm−2, which are 12.6- and 17.2-fold higher than those of commercial Pt/C catalysts, respectively. Density function theory calculations suggest that the incorporation of Ni can weaken Pt-OH overbinding effect on the (100) facets, promoting hydrogenation of *OH. The free energy changes in the potential-limiting step demonstrate that the (100) facets are more active. This work is expected to provide new view on the rational designing of nanocatalysts facets. Pt1.4Ni tetrapods enclosed by (100) facets as efficient oxygen reduction reaction catalysts.