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A Solar-Powered Microbial Electrolysis Cell With a Platinum Catalyst-Free Cathode To Produce Hydrogen

Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea.
Environmental Science and Technology (Impact Factor: 5.33). 12/2009; 43(24):9525-30. DOI: 10.1021/es9022317
Source: PubMed

ABSTRACT

This paper reports successful hydrogen evolution using a dye-sensitized solar cell (DSSC)-powered microbial electrolysis cell (MEC) without a Pt catalyst on the cathode, indicating a solution for the inherent drawbacks of conventional MECs, such as the need for an external bias and catalyst. DSSCs fabricated by assembling a ruthenium dye-loaded TiO(2) film and platinized FTO glass with an I(-)/I(3)(-) redox couple were demonstrated as an alternative bias (V(oc) = 0.65 V). Pt-loaded (0.3 mg Pt/cm(2)) electrodes with a Pt/C nanopowder showed relatively faster hydrogen production than the Pt-free electrodes, particularly at lower voltages. However, once the applied photovoltage exceeded a certain level (0.7 V), platinum did not have any additional effect on hydrogen evolution in the solar-powered MECs: hydrogen conversion efficiency was almost comparable for either the plain (71.3-77.0%) or Pt-loaded carbon felt (79.3-82.0%) at >0.7 V. In particular, the carbon nanopowder-coated electrode without Pt showed significantly enhanced performance compared to the plain electrode, which indicates efficient electrohydrogenesis, even without Pt by enhancing the surface area. As the applied photovoltage was increased, anodic methanogenesis decreased gradually, resulting in increasing hydrogen yield.

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    • "Recently, a significant number of researchers have reported that the performance of MEC is greatly influenced by several factors, such as initial pH, temperature [4] [5], electrolyte solution [6e9], substrates and anode surface area [10e12], microbial anode potential (MAP) [13], electrode materials and electrode spacing [14] [15], cell internal and external resistance [16e18], and activated sludge concentration [19]. Of these factors, cathode material with the high performance is the most important factor in the performance of MECs where H 2 as well as other value-added chemical compounds are produced. "
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    ABSTRACT: Microbial electrolysis cells (MECs) are generally regarded as a promising future technology for manufacturing green hydrogen from organic material present in wastewaters and other renewable energy sources. However, the development of inexpensive and high-efficient cathode catalyst is the most critical challenge for MECs to become a commercialized H2 production technology. In this study, a non-noble metal electroformed Ni mesh cathode alternatives to typical cathode material (Pt/CC) was intensively examined in a single-chamber membrane-free MEC. To the best of our knowledge, the use of electroformed Ni mesh as the MEC cathode catalyst has not been reported so far. The MEC was operated in fed-batch mode and the performance of the Ni mesh cathode was compared with that of Pt/CC cathode in terms of columbic efficiencies (75 ± 4% vs. 72.7 ± 1%), overall hydrogen recovery (89.3 ± 4% vs. 90.9 ± 3%), overall energy efficiency (62.9 ± 5% vs. 69.1 ± 2%), the maximum volumetric hydrogen production rate (4.18 ± 1 m3 H2/m3 d vs. 4.25 ± 1 m3 H2/m3 d), volumetric current density (312 ± 9 A/m3 vs. 314 ± 5 A/m3). The obtained results in this study highlight the great potential of using the electroformed Ni mesh catalysts as a viable cathode material for hydrogen production in MECs.
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    • "In this system, the MFC acted as an external energy source to produce hydrogen at the MEC cathode. A solar-powered MEC with a Pt catalyst-free cathode was reported for the production of hydrogen (Chae et al., 2009). Because both the MFC and solar cell use renewable energy, the application of them as the external energy sources for MEC operation can extend this technology in practical fields. "
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    Full-text · Article · May 2013 · Biotechnology Advances
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    • "MEC ARB Acetate – 9.42 Chae et al. (2009) the existing systems. Particularly, the granule-based reactors, thermophilic processes, and integrated systems hold great promise for practical application, but many challenges are yet to be addressed. "
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