1. Ammonia-treated brown coal and its activity for oxygen reduction reaction in polymer electrolyte fuel cell
- Author
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Muraoka, Mitsuyoshi, Tomonaga, Hiroyuki, and Nagai, Masatoshi
- Subjects
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LIGNITE , *AMMONIA , *PROTON exchange membrane fuel cells , *CHEMICAL reduction , *METAL catalysts , *RAMAN spectroscopy , *NITROGEN absorption & adsorption - Abstract
Abstract: Coal has been utilized as a nonprecious metal catalyst for the oxygen reduction reaction (ORR) in a polymer electrolyte fuel cell. The Australia brown coal was nitrogen-doped at 673–1123K in a stream of NH3. The raw and NH3-treated Australia brown coals were characterized on the basis of their N2 adsorption, Raman spectroscopy and X-ray photoelectron spectroscopy. The nitrogen doping of the coal at 1073K increased the BET surface area from 10 to 671m2/g having 95% slit-shaped micropores with a type I monolayer adsorption. The nitrogen-doped coal at 1073K exhibited the highest potential of 0.85V vs. RHE (at −0.005mA/cm2), which was evaluated by three-electrode electrochemical measurements using a rotating ring disk electrode in a 0.5M H2SO4 aqueous solution. The ORR activity of the nitrogen-doped coal was related to the pyridine-N species, microporosity and degree of disordered carbons in the coal. The iron addition to the coal from 10 to 103 ppm increased the ORR onset potential. The active structure of the coal-derived catalyst was discussed based on the results of the XPS, Raman, N2 adsorption and iron effect. [Copyright &y& Elsevier]
- Published
- 2012
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