Shape and structural effects of R5-templated Pd nanomaterials as potent catalyst for oxygen electroreduction in alkaline media

Bio-inspired metal nanomaterials are receiving increasing research attentions in catalytic field recently, while peptide-based method represents new revenues to fabricate stable and reactive catalyst under mild and environmental friendly conditions. Among all kinds of noble metals, peptide-based palladium nanomaterials have demonstrated excellent catalytic capabilities in a variety of organic reactions. However, their electrocatalytic properties have not been systematically studied. Herein, R5-templated Pd nanomaterials have been fabricated and employed as potent catalysts for oxygen reduction reaction (ORR). The shape and morphology of these Pd nanomaterials were manipulated by tuning the metal-to-R5 ratio. The as-prepared Pd nanomaterials demonstrated excellent ORR activity in alkaline media. R5-Pd-90 exhibited the best activity which is superior than commercial Pt/C, in terms of onset potential, diffusion-limited current density as well as long-term stability. The correlation between the shape and/or morphology of the peptide-templated Pd nanomaterials and their ORR activity has been successfully established.