Zinc-assisted synthesis of Fe-N-C catalysts based on polyaniline with high oxygen reduction reaction catalytic activities in direct methanol fuel cells

Fe-N-C catalysts show great potential to replace Pt/C in oxygen reduction reaction (ORR). Polyaniline (PANI) is an ideal precursor with an abundant and homogeneous distribution of nitrogen sources. However, Fe-N-C based on PANI suffers from an unsatisfied performance in acidic media. Herein, a facile zinc-assisted synthesis of Fe-N-C based on PANI was reported in this paper. ZnCl₂ templates can be removed completely in the pyrolysis procedure, creating abundant porous structures to accelerate the mass transfer and boost ORR performance. Fe-N-C-2 with the adequate and optimizing amount of zinc shows an excellent ORR performance (E_1/2 = 0.91 V in alkaline and E_1/2 = 0.825 V in acidic media) compared with Pt/C (E_1/2 = 0.89 V in alkaline and E_1/2 = 0.84 V in acidic media). Furthermore, a high power density and a long-term operation within 6 h of direct methanol fuel cell based on brilliant Fe-N-C-2 verify a great promising application of potable power devices in the future.