| Microbial fuel cell (MFC) directly converts the organics to electricity and it is able togenerate electricity and accomplish pollutant treatment simultaneously. So MFC hasbecoming a new research direction in the field of environmenetal engineering. Amongmany different types of MFC, air-cathode microbial fuel cell (ACMFC) shows promisingcharacteristics because it cathode use the oxygen in the air as oxidant. But due to thesluggish kinetics of the ORR, platinum (Pt) is common used to accelerate the oxygenreduction process, the expensive Pt dramatically increases the cost of ACMFCs, whichlimits the development of MFC. The relative research on ACMFCs is still limited to thelaboratory scale. Reducing the cost of ACMFC, while keep its high electricity generationcapacity is becoming an urgent problem to be solved in the field of research on ACMFC.In this study, we self-assemblied single chamber MFC, to reduce the cost and improve theORR performance, we alloying Pt with other low-cost metals and supported on the carbonmaterials. And we mainly have done the following three studies.1. We used NaBH4as reducing agent to deposit Pt-Ni nanoparticles on carboxylmulti-wall carbon nanotubes, Pt-Ni/MWNT (atomic ratio, Pt: Ni=1:1,15wt%Pt) X-raydiffraction (XRD) and transmission electron microscopy (TEM) measurements wereemployed to observe the catalyst characterization. We also investigated its performance inan air cathode single chamber MFC. Pt-Ni/MWNT exhibit about the same catalytic activitytowards ORR compared to pure platinum catalyst, while the price of a Pt-Ni/MWNTcatalyst was approximately three-quarter of Pt/C catalyst.2. The graphite oxide was prepared by modified Hummers method, graphene wasobtained by ultrasonic stripping the graphene oxide then reduced by glycol reflux. Highcatalytic activity of Pt-Co/G (15wt%Pt) alloy particles are synthesized on reducedgraphene oxide (RGO). XRD and TEM measurements were employed to observe thecatalyst structure and size distribution. We also investigated its performance in an aircathode single chamber MFC. For comparison, a commercially available oxygen reductionelectrocatalyst of20wt%Pt/C was also exprimented. The activity of Pt-Co/G towards ORR was much close to to pure platinum catalyst, while the price of Pt-Co/G catalyst wasapproximately was reduced by about25%. Pt-Co/G showed a great potential to be used asa cost-effective catalyst in air cathode of MFCs.3. A series of nanostructure Pt-Co alloy catalysts with varying Pt:Co ratio by EGstabilized NaBH4reduction at room temperature, and they are successfully applied to theair cathode MFC. Pt-Co/C exhibited the highest mass activity, the enhancement factors formass activity were found to be2.8times versus commercial Pt/C, and the stablity are alsoimproved.4. Three carbon-supported PtxFe alloy electrocatalysts with varying Pt:Fe atom ratio(Pt3-Fe/C, Pt2-Fe/C, Pt-Fe/C) were prepared by simple NaBH4reduction in glycerol atroom temperature. Electrocatalytic performance of synthesized PtxFe alloy catalysts wascompared with commercial Pt/C using cyclic voltammetry and linear sweep voltammetry,among these NPs, Pt3-Fe/C catalyst exhibits the highest activity and the best stability foroxygen reduction reaction (ORR) in both acidic and neutral media. As the cathode catalyst,the maximum power density produced from microbial fuel cell with Pt3-Fe/C (1680±15mW m-2) was18%higher than that with conventional Pt/C (1422±18mW m-2), and thestability of Pt3-Fe/C was greatly improved. |
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