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We report on the design of a bio‐inspired composite as a noble‐metal‐free electrocatalyst for the oxygen reduction reaction (ORR). The composite is made from the assembly of pyridine‐functionalized graphene (G‐py) and a 3 D metal–organic framework (MOF) deposited onto a glassy carbon electrode (GCE). The 3 D heme‐like MOF was synthesized from tetrakis(4‐carboxyphenyl)porphyrin iron(III) chloride and Zr6 clusters for the assembly of the stable porous coordination network. G‐py, which possesses an axial ligand to anchor to the centers of porphyrin in the MOF, results in a significant change in the electronic and geometric structure of centers, which enhances the rate of ORR and durability during cycling in acidic media. The occurrence potential of the ORR by the composite is shifted to the positive potential near 100 mV. Our results introduce a new strategy for the rational design of inexpensive and highly stable oxygen reduction electrocatalysts for fuel cells without the requirement of pyrolysis.

Synthesis, spectroscopy, and crystal structures of [Cu(ca 2 en) 2 ]ClO 4 (1) and [Cu(ca 2 en)(PPh 3 ) 2 ]ClO 4 (2) (ca 2 en N,N'-bis(trans-cinnamaldehyde)ethylenediimine) are reported. Compound 1 crystallizes in the orthorhombic space group Pbca, with a 12.5647 (7), b 21.8203(11), c 27.992(2) ä, V 7674.3(7) ä 3 , Z 8. Compound 2 crystallizes in the triclinic space group P1 ≈ , with a 13.0540(11), b 14.2935(13), c 14.9863(13) ä, a 84.130(2), b 69.761(2), g 87.749(2)8, V 2609.8(4) ä 3 , Z 2. The coordination polyhedron about the Cu I center in the two complexes is best described as a distorted tetrahedron. The 1 H-NMR and electronic spectra of these complexes are also reported and discussed. The cyclic voltammetry of the complexes indicate a quasireversible redox behavior for complex 1 (E 1/2 0.51 V). However, complex 2 displays an irreversible oxidation wave at 0.91 V. A weak emission is observed for complex 2 in CHCl 3 at room temperature.