Fe(Ⅲ)-EDTA作为阴极电子穿梭体的微生物燃料电池持续产电机制 |
摘要点击 3134 全文点击 2252 投稿时间:2008-08-08 修订日期:2008-10-27 |
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中文关键词 微生物燃料电池 电子穿梭体 Fe(Ⅲ)-EDTA 氧化再生 Klebsiella pneumoniae L17 |
英文关键词 microbial fuel cell(MFC) electron shuttle Fe(Ⅲ)-EDTA oxidation regeneration Klebsiella pneumoniae L17 |
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中文摘要 |
阴极氧还原反应(ORR)是影响微生物燃料电池(microbial fuel cell,MFC)性能的重要因素.采用双室MFC以Fe(Ⅲ)-EDTA为阴极液进行持续产电试验.结果表明,添加Fe(Ⅲ)-EDTA作为阴极液可显著加速氧还原反应速率,降低内阻,提高输出电压与功率.当阴极液中存在20.0 mmol/L的Fe(Ⅲ)-EDTA时,电池内阻仅为300 Ω,比对照降低了900 Ω,其输出电压(1 000 Ω下)与功率密度可维持在200.1 mV、 16.0 mW/m2左右,比不加的对照分别提高73.2%、 70.1%. Fe(Ⅲ)-EDTA氧化再生与持续产电试验表明,Fe(Ⅲ)-EDTA可通过曝气氧化再生、循环利用,即Fe(Ⅲ)-EDTA可作为阴极电子穿梭体加速电子至氧气的传递.Fe(Ⅲ)-EDTA首先接受阴极电子被还原成Fe(Ⅱ)-EDTA,在阴极室充分曝气条件下,Fe(Ⅱ)-EDTA将电子传递给O2同时被氧化再生成Fe(Ⅲ)-EDTA,从而完成电子从电极传递到氧气的穿梭过程,MFC得以长期稳定运行.进一步优化试验显示,Fe(Ⅲ)-EDTA作为阴极电子穿梭体强化MFC产电的适宜条件为:浓度20.0 mmol/L、pH=5.0左右.在此条件下MFC的最大功率密度达100.9 mW/m2. |
英文摘要 |
The rate of oxygen reduction reaction (ORR) at the cathode is a major factor affecting the performance of the microbial fuel cells(MFC). Results showed that when using Fe(Ⅲ)-EDTA solution as catholyte,the ORR rate was significantly increased and the internal resistance was reduced,consequently leading to an increase in power output. With a concentration of Fe(Ⅲ)-EDTA at 20.0 mmol/L in the catholyte,the MFC produced the voltage and power density at approximate 200.1 mV and 16.0 mW/m2,respectively,which was increased by 73.2% and 70.1% contrary to the MFC without the presence of Fe(Ⅲ)-EDTA. The further experiment suggested that Fe(Ⅲ)-EDTA functioned as electron shuttle to accelerate electron transfer. Fe(Ⅲ)-EDTA received electron and got reduced to Fe(Ⅱ)-EDTA,which further provided electrons to oxygen and got reoxidized at the same time. Therefore Fe(Ⅲ)-EDTA can act as recyclable electron shuttles between cathode electrode and oxygen. The optimum condition in the case of using Fe(Ⅲ)-EDTA as cathode electron shuttles was tested to be Fe(Ⅲ)-EDTA concentration at 20.0 mmol/L and pH at 5.0,which allowed MFC produced the maximum power density of 100.9 mW/m2. |