Metal-Organic Coordination Networks: Prussian Blue and Its Synergy with Pt Nanoparticles to Enhance Oxygen Reduction Kinetics

Oxygen reduction reaction (ORR) is the cornerstone in the electrochemical energy conversion devices such as fuel cells and metal-air batteries. It remains a great challenge to develop the ORR electrocatalysts with fast kinetics and high durability. Herein, we report the synthesis of a novel metal-organic coordination networks material, prussian blue crystalline nanograins mosaicked within amorphous membrane (PB CNG-M-AM). Such unique PB CNG-M-AM is designed to enhance the electrocatalysis of Pt toward the ORR by the electrostatic self-assembly. Thus, obtained Pt-PB/C catalysts form numerous Pt-PB-gas three-phase boundaries and present rather high intrinsic activity, four-electron selectivity and superior stability. Moreover, a completely new synergetic mechanism between PB and Pt is discovered, which delicately alters the ORR route and significantly enhances the ORR kinetics. This work provides not only a new strategy and mechanism for developing highly efficient ORR electrocatalysts, but also an alternative way to utilize metal-organic coordination networks materials.