Article ID Journal Published Year Pages File Type
5432224 Carbon 2017 15 Pages PDF
Abstract

(Co)polycondensation of resorcinol and heterocyclic aldehydes yields heteroaromatic porous polymers. Carbonization of such polymers results in N-doped, S-doped, N/S-co-doped or undoped carbon gels depending on the starting composition of reactants. If the (co)polycondensation is initiated with FeCl3, Fe-containing carbon gels are obtained. Depending on the nature of the heteroatom doping (solely N or S, both N and S or no heteroatom) the Fe-containing carbon gels exhibit distinct structural properties. While the presence of sulfur hinders Fe-driven graphitization, yielding carbons with high specific surface area (SSA), N-doping exhibits the contrary effect, resulting in highly graphitic structures with low SSAs. More importantly, increasing the Fe content in the N/S-co-doped carbons results in remarkable increases in microporosity, yielding materials with SSA of up to 1240 m2g-1. The Fe-containing carbon gels are considered non-precious metal catalysts for the oxygen reduction reaction. It is demonstrated that in the case of Fe/N/C/S type catalysts, the interaction between S, C and Fe (at the pyrolysis stage) results in the enhancement of microporosity, where S acts as a soft oxidant toward carbon, while Fe recaptures the sulfur- and carbon-containing pyrolytic gases. The incidental deposition of pyrolytic gases contributes significantly to the final structure of the catalysts.

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Physical Sciences and Engineering Energy Energy (General)
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