Excellent Oxygen Reduction Reaction Performance in Self-Assembled Amyloid-β/Platinum Nanoparticle Hybrids with Effective Platinum-Nitrogen Bond Formation

The development of highly efficient catalysts for electrochemical oxygen reduction reactions (ORRs) is crucial for energy applications such as metal-air batteries and fuel cells. Here, we show an enhanced electrocatalytic activity of a new functional material composed of Pt nanoparticles (PtNPs) and self-assembled beta-sheet peptides (beta Ps). The PtNP/beta P hybrids, under an optimized assembly condition, display an ORR electrocatalytic activity that is higher than that of a commercially available benchmark Pt/C electrocatalyst in terms of the onset potential and reaction kinetics. Moreover, the PtNP/beta P hybrids show one order of magnitude higher ORR N-300 mass activity than previously reported peptide-based ORR electrocatalysts. The superb ORR activity with high durability is derived from the well-dispersed PtNPs on beta Ps, where 50% of the amine groups on the side chain bound with Pt to form Pt-N bonds that function as active sites for the catalytic reaction. This work opens new avenues for efficient ORR electrocatalysts using self-assembled peptides.