Coals as a novel cathode catalyst for polymer electrolyte fuel cell

Coal has been developed as a new non-noble metal cathode catalyst for a polymer electrolyte fuel cell. The activities of four ranks of coals (anthracite, bituminous, sub-bituminous and brown coals) for the oxygen reduction reaction (ORR) were determined based on heat treatment in streams of various gases, nitridation and the iron addition effect. The surface area depended on the micropores of the nitrided coals distributed at 85-96%, thus showing extremely higher internal microporous surface areas. The XRD measurement suggested that the tested coals had a domain assembly composed of microdomains of approximately three layers of graphene with an interlayer distance of 0.37 nm and a layer length of 1.15 nm. The high-power decoupling CP/MAS C-13 NMR analysis of the nitrided Adaro coal showed the presence of little hydrogen in the fringe of the fused aromatic compounds of the nitrided coal. The treatment of the coals in a stream of NH3 exhibited a higher ORR potential vs. RHE than those in the nitrogen and 20% CH4/H-2 streams. The 1073 K-nitrided brown and sub-bituminous coals were significantly active for the ORR, while the nitrided anthracite coal was less active. Based on the XPS analysis, the introduction of nitrogen atoms formed a deficit structure with the pyridinic nitrogen. (C) 2011 Elsevier Ltd. All rights reserved.