甲烷生物燃料电池的产电影响因素及机制研究

考察了阳极电极材料、电极面积、电极电位、pH、阴极电子受体对甲烷生物燃料电池（MFC）产电性能的影响，并通过高通量测序、循环伏安法（CV）分析了其可能的电催化机制.结果表明，透气布/碳布（GTC）复合材料为阳极时产电性能（1251.3 mA·m^-2）最佳，分别是石墨烯/中空纤维膜（G-HFM）阳极（34.8 mA·m^-2）和碳布（CC）阳极（3.21 mA·m^-2）的36倍和390倍；阳极面积越大，MFC启动时间越快，电流密度越大；当电极恒电位为0.1 V （vs.SHE）时，其产电能力较-0.1、+0.3及+0.5 V时高；pH=7最有利于产电；溶解氧为MFC阴极电子受体时，最大功2率密度（703.9 mW·m^-2）优于铁氰化钾（457.2 mW·m^-2）、空气阴极（124.2 mW·m^-2）和高锰酸钾（20.7 mW·m^-2）作为电子受体的MFC.阳极室微生物群落结构分析显示，电活性细菌Geobacter（17.14%）和Desulfovibrio（8.51%）为优势种，其产电机理可能是甲烷氧化菌（Methanobacterium、Methylomicrobium等）与电活性细菌协同氧化甲烷驱动MFC产电.添加NO气体、N-乙酰蛋氨酸和蛋白酶K均可明显抑制阳极生物膜的电化学活性，表明其胞外电子传递过程依赖细胞色素c、Ni-Fe氢酶及与电极接触的外膜蛋白的介导作用.

Research on the influencing factors and mechanisms of electricity generation of methane-driven microbial fuel cell

The effects of anode material, electrode area, electrode potential, pH and cathode electron acceptor on the electricity generation of methane-driven microbial fuel cell (MFC) were investigated in this paper, and cyclic voltammetry (CV) and high-throughput sequencing were performed to reveal the possible electrocatalytic mechanisms. The results showed that the gas diffusion cloth/carbon cloth (GTC) composite anode showed the best performance (1251.3 mA·m^-2), which was 36 times and 390 times higher than that of graphene/hollow fiber membrane (G-HFM) anode (34.8 mA·m^-2) and carbon cloth (CC) anode (3.21 mA·m^-2), respectively. The larger the anode area, the higher the current density generated and the faster the reactor started up. When the electrode potential was poised at 0.1 V (vs. SHE), the power generation was the highest than those with potentials poised at -0.1 V, +0.3 V and +0.5 V. The most favorable pH for power generation was 7. When dissolved oxygen was served as the electron acceptor, the maximum power density (703.9 mW·m^-2) was much higher than those with potassium ferricyanide (457.2 mW·m^-2), air cathode (124.2 mW·m^-2) and potassium permanganate (20.7 mW·m^-2) as electron acceptors. The microbial community structure in anode chamber was dominated by Geobacter (17.14%) and Desulfovibrio (8.51%). Thus, the mechanism of electricity generation in MFC was speculated to be the synergistic cooperation between methanotrophs (Methanobacium, Methylomicrobium) and electroactive bacteria. The addition of NO gas, N-acetylmethionine and proteinase K could significantly inhibit the electrochemical activity of the anodic biofilm, indicating that the extracellular electron transfer process was mainly mediated by cytochrome c, Ni-Fe hydrogenase and outer membrane proteins contacted with anode.