Bimetallic−organic framework-derived hierarchically porous Co-Zn-N-C as efficient catalyst for acidic oxygen reduction reaction

Abstract

The development of highly active and cost-efficient electrocatalysts toward oxygen reduction reaction (ORR) is essential for widespread application of polymer electrolyte fuel cell (PEFC). In the present work, hierarchically structured porous Co-Zn-N-C electrocatalyst is prepared by using soft templated bimetallic-organic framework precursors. The as-synthesized hierarchically porous catalyst presents outstanding ORR onset-potential (0.88 V vs. RHE), half-wave potential (0.78 V vs. RHE), and diffusion limiting current density (5.73 mA cm−2), that is similar to that at commercial Pt/C catalyst in acidic electrolyte. It is found that the hierarchical porous architecture is important for its excellent catalytic activity and further testifies that the hierarchically porous electrocatalyst also exhibits superior single PEFC performance with a power density of 412 mV cm−2. The present work provides not only a facile and low cost strategy toward the preparation of hierarchically porous materials, but also inspires an approach for enhancing the ORR electrocatalytic activity of MOF-derived materials. © 2018 Elsevier B.V.