title: Biomass-derived nitrogen self-doped porous carbon as effective metal-free catalysts for oxygen reduction reaction.
abstract: Biomass-derived nitrogen self-doped porous carbon was synthesized by a facile procedure based on simple pyrolysis of water hyacinth (eichhornia crassipes) at controlled temperatures (600-800 °C) with ZnCl2 as an activation reagent. The obtained porous carbon exhibited a BET surface area up to 950.6 m(2) g(-1), and various forms of nitrogen (pyridinic, pyrrolic and graphitic) were found to be incorporated into the carbon molecular skeleton. Electrochemical measurements showed that the nitrogen self-doped carbons possessed a high electrocatalytic activity for ORR in alkaline media that was highly comparable to that of commercial 20% Pt/C catalysts. Experimentally, the best performance was identified with the sample prepared at 700 °C, with the onset potential at ca. +0.98 V vs. RHE, that possessed the highest concentrations of pyridinic and graphitic nitrogens among the series. Moreover, the porous carbon catalysts showed excellent long-term stability and much enhanced methanol tolerance, as compared to commercial Pt/C. The performance was also markedly better than or at least comparable to the leading results in the literature based on biomass-derived carbon catalysts for ORR. The results suggested a promising route based on economical and sustainable biomass towards the development and engineering of value-added carbon materials as effective metal-free cathode catalysts for alkaline fuel cells.
authors.affiliation: New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong 510006, China. eszhouwj@scut.edu.cn shaowei@ucsc.edu.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Liu
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Zhou
authors.forename: Weijia
authors.initials: W
authors.lastname: Zhou
authors.forename: Ligui
authors.initials: L
authors.lastname: Li
authors.forename: Shaobin
authors.initials: S
authors.lastname: Huang
authors.forename: Shaowei
authors.initials: S
authors.lastname: Chen
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D031806:Eichhornia / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D016062:Porosity
chemical_list: D002244:Carbon; D009584:Nitrogen; D010100:Oxygen