N-doped Porous Carbon Electrocatalyst Treated with Fe Surface Properties and Electrocatalytic Activity

Abstract

Pt and Pt alloys loaded on carbon support suffer from high cost and low durability of the noble metal electrocatalyst in fuel cell. Recently, non-Pt based heteroatom-doped carbon catalysts, due to their high stability, excellent electrocatalytic performance, and economic viability over costly Pt-based catalysts are being pioneered as a suitable alternative. Although the heteroatom-doped porous carbon materials have evolved as one of best possible solutions, the probable synergy of heteroatom doping and textural properties has not been well investigated yet in details. Active species, electrical conductivity, porous structure and surface area are the key factors affecting overall electrocatalytic activity of carbon-based electrocatalysts [3]. In this work, we report Fe-treated N-doped porous carbons (Fe/NPC) as oxygen reduction reaction (ORR) catalysts through pyrolysis of iron phthalocyanine (FePc)- infiltrated SBA-15 silica. Excellent ORR activity with a nearly four-electron transfer process is observed for the Fe/NPC prepared with FePc in both alkaline and acidic media. Interestingly, it is found that although Fe is necessary for the preparation of highly active N-doped carbon catalyst, its presence may be not necessary for N-doped porous carbon to be active in the ORR in either alkaline or acidic media. The ORR activity is discussed in terms of heteroatom content, surface area, porous structure, and conductivity of the carbon.