Study Of The Influence Of Air Cathode Catalysts And Electrode Array Scale-up On The Performance Of Microbial Fuel Cell(MFC)

Microbial fuel cell(MFC)is an electrochemical device that converts chemical energy into electrical energy through catalytic decomposition of microorganisms.Because MFC can generate electrical energy while removing organic matter,it has a very broad application prospect in sewage treatment.There are many types of decomposable organic matter in MFC,and even some complex organic matter in sewage can be directly oxidized and decomposed.The cost of MFC operation and maintenance is low,the operation is mild,and it has obvious advantages in sewage treatment.However,the lower power output of MFC is an important factor limiting its practical application.On the one hand,the electrical performance of single-chamber MFC is often affected by the air cathode limits.On the other hand,in order to meet the actual sewage treatment requirements,the power density of the laboratory-scale reactor is seriously reduced during the amplification process.This seriously hindered the MFC’s practical process.In this paper,the following research is carried out to solve the above problems:1.Effect of Air Cathode Loaded Solid Acid on Electricity Performance of Single Chamber MFCSolid acid(sulfated zirconia)was supported as a cathode catalyst in an activated carbon air cathode and its oxygen reduction catalytic performance was investigated for the first time.LSV characterization showed higher open circuit potential and catalytic current for air cathodes loaded with sulfated zirconia.The power density of air cathode loaded with sulfated zirconia obtained in MFC is significantly higher than the power density of AC air cathode in MFC,However,during the long-term operation,the electric performance of the air cathode loaded with solid acid decreases.The experiment shows that this is due to the solid acid in the air cathode entering the solution and being further lost with the replacement of the culture medium.Sulfated zirconia provides a new choice of catalysts for MFC cathode performance improvement.2.Carbamazepine as a precursor for synthesis of Fe-N-C catalyst and its catalytic performance study in MFC air cathodeCarbamazepine(Ci5H12N2O2 5H-dibenz[b,f]azepine-5-carboxamide),as an organic precursor,was used for the first time to synthesize Fe-N-C catalysts for air cathode applications in MFCs.The synthesized catalysts,Fe-CBZ,with porous structures and uniformly dispersed Fe/N/C complex centers,were obtained.LSV characterization and long-term operation in MFC show that the synthesized Fe-CBZ catalyst has catalytic performance equivalent to commercial Pt/C.The maximum power density produced by cathode-limiting MFCs with Fe-CBZ air cathodes among the highest reports in literatures.Moreover,the toxicity tolerance of the present Fe-CBZ is higher than commercial Pt/C.Carbamazepine provides an important reference for the selection of organic precursors for the synthesis of highly efficient Fe-N-C oxygen reduction catalysts.3.Study on the Influence of Electrode Matrix Amplification Method on MFC PerformanceAn MFC scale-up method is designed that distributes electrode pairs in a matrix and expands arbitrarily in the horizontal direction and MFC is constructed to verify its feasibility.The result shows that the power density does not decrease with the increase of device volume.This result contrasts with the general result that the output power of MFC devices reported in the literature shows a significant decrease as the device size increases.The measurement of internal resistance found that the internal resistance of MFC did not increase with the increase of device volume.The volume of the device has no obvious influence on the organic matter removal ability and coulomb efficiency of MFC,but the connection mode of external resistance has a greater influence on the coulomb efficiency of MFC.The device expansion method has important reference value in the actual application process of MFC.