The intriguing ORR performance of iron and nitrogen co-doped biomass carbon composites incorporating surface-modified polyaniline-derived carbon

As a clean energy conversion device, fuel cell can greatly alleviate the environmental pollution problem. Developing cost-effective oxygen reduction reaction (ORR) catalysts with high performance is of great signifi-cance to improve the efficiency of fuel cells and promote its large-scale use. Here, we successfully fabricated an iron and nitrogen co-doped carbon-carbon composite (Fe-N-C-B350-900Z@C-PANI) by modifying a pre-synthesized iron and nitrogen co-doped biomass carbon (Fe-N-C-B350-900Z) with polyaniline derived carbon (C-PANI). The obtained Fe-N-C-B350-900Z@C(PANI )displays excellent ORR catalytic activity, as reflected by the positive onset potential of 0.13 V vs Hg/HgO and high limiting current density of 5.92 mA cm(-2), which significantly out-performs the benchmark Pt/C (0.07 V and 4.70 mA cm(-2), respectively). Meanwhile, it also presents remarkable catalytic stability and the great methanol tolerance. The excellent catalytic performance of Fe-N-C-B350- 900Z@C-PANI is attributed to the merits of the hierarchical porous structure and large specific surface area up to 955 m(2) g(-1) formed by synergism of C-B and C-PANI, which effectively promotes the mass transfer and accessibility of active sites.