A Highly Active and Support-Free Oxygen Reduction Catalyst Prepared from Ultrahigh-Surface-Area Porous Polyporphyrin

摘要

A new approach for preparing non-precious-metal electrocatalysts using a porous organic polymer (POP) as precursor is presented. Polyporphyrin, containing a high density of nitrogen-coordinated iron macrocyclic centers, was prepared by oxidative coupling to form a porous network with a very high specific surface area and narrow pore-size distribution. Upon pyrolysis, the POP was converted into a highly active electrocatalysts for the oxygen reduction reaction in an acidic electrolyte. Proton-exchange membrane fuel cells, prepared with such catalyst at the cathode, achieved very high measured volumetric and gravimetric current densities of 20.2 A cm~(-3) and 39.4 A g~(-1) at 0.8 V, respectively, and a peak power density of 730 mWcm~(-2) at 0.4 V.