| Summary: | 碩士 === 國立中正大學 === 化學工程研究所 === 107 === Zinc air battery (ZAB) is one of the most important research fields in energy storage application. The study of ZAB mainly development focuses on the catalysts with high efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) so that the battery is capable of conducting with charging and discharging processes. In this study, carbon-nanotube (CNT) -grafted and Co3O4-doped porous carbon was prepared by the carbonization of the synthesized zeolitic imidazolate framework (ZIF-67/ZIF-8) compound followed by an oxidation treatment. The novel catalyst demonstrated excellent ORR and OER because of the Co3O4 nanoparticles and nitrogen-doped in the carbon framwork (NC). In addition, the carbon nanotube grafted on the framework provided a good electrical conductivity while the carbon framework matrix provided a porous skeleton which is beneficial for the mass transfer of electrolyte. In the ORR study, the novel catalyst, CNT-Co3O4/NC, showed a half-wave potential of -0.124 V at 0.1 M KOH (Pt/carbon: -0.152 V) while the limited current density is 4.84 mA/cm2 (Pt/ carbon: 4.9 mA/cm2). In terms of OER performance, the potential is 0.819 V at current density of 10 mA/cm2 (Ir/carbon: 0.771 V). In the ZAB study, with CNT-Co3O4/NC catalyst, a specific capacitance of 814 mAh/g (1.19 V at 50 mA/cm2) was obtained, which is very close to the theoretical capacitance (820 mAh/g) and maximum power density was 267 mW/cm2 (0.746 V at 385 mA/cm2) while 255 mW/cm2 (0.711 V at 360 mA/cm2) was obtained using Pt/carbon catalyst. We believe that the novel CNT-Co3O4/NC can be used as an excellent catalyst in the zinc-air battery.
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