One-step synthesis of Fe3PtPd(OH)2[Picolinic acid]8(H2O)4 hybrid nanorods: efficient and stable electrocatalyst for oxygen reduction reaction in alkaline solution

Abstract

Design and synthesis of effective electrocatalysts for oxygen reduction reaction in alkaline environments is critical to reduce energy losses in alkaline fuel cells. We have systematically evaluated new approaches for reducing the Pt content while retaining the activity of a Pt-based catalyst with hydrolytic phases containing hydroxide moieties in addition to metal ions and ligands. We report for the first time architectured organic-inorganic hybrid nanorod catalyst, which is fabricated by solvothermal reaction of K2MCl4 (M = Pd, Pt) with picolinic acid (PA) (chelating agent) in the presence of FeCl2. Excess base produces isostructural coordination M-PA complex to Fe-OH chains. A generic formula can be written as Fe3PtPd(OH)2[PA]8(H2O)4. The electrocatalytic activities of the hybrid nanorods are explored for oxygen reduction reaction (ORR) in alkaline medium. The onset potential of ORR is significantly reduced with a positive shift of about 109 mV and twice the reduction current density is observed in comparison with Pt/C with the same mass loading. We believe that this work may lead towards the development of heterodoped organic- inorganic hybrid materials with greatly enhanced activity and durability for applications in catalysis and energy conversion.