One-Pot Synthesis of Icosahedral PdPtNi/C Twin Crystal Catalyst with High Activity toward Oxygen Reduction Reaction

Abstract

Pt and Pt-based alloys are still the mainstream electrocatalysts for oxygen reduction reaction (ORR) so far, which is an important process for fuel cell. Herein, for the first time ternary icosahedral nanocrystals supported on carbon PdPtNi/C are constructed by a facile one-pot approach and are characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The electrocatalytic performance of the as-prepared catalyst for ORR is evaluated in acid electrolyte and compared with the state-of-the-art commercial Pt/C catalyst at identical condition. The icosahedral structure with 20 exposed {111} facets and twin boundaries are the distinguishing features of the PdPtNi/C nanoparticles, which enable them to be more active. The compressive strain effect and electronic interaction (ligand effect) of Pd, Pt, and Ni elements are also responsible for the excellent performance of the catalyst: the higher onset potential of ORR than that of commercial Pt/C, the outstanding specific activity and mass activity, which is about 9.59 and 5.40 times higher than those of commercial Pt/C at 0.90 VRHE, respectively, while 5.39 and 4.75 times higher at 0.85 VRHE, respectively. These results can promote the practical application of Pt-based catalyst and thus accelerate the widespread commercialization of fuel cell technologies.