Promoted electromethanosynthesis in a two-chamber microbial electrolysis cells (MECs) containing a hybrid biocathode covered with graphite felt (GF)

Guangyin Zhen, Xueqin Lu, Takuro Kobayashi, Gopalakrishnan Kumar, Kaiqin Xu

Research output: Contribution to journalArticlepeer-review

61 Citations (Scopus)

Abstract

Microbial electromethanogenesis, relying on electrochemically active biofilm on biocathode to convert carbon dioxide to methane, provides a novel approach for renewable energy storage. One key factor that governs electron exchange and methane formation efficiencies is the electrode material. To promote methane production, a biocathode via modifying plain carbon stick with a layer of graphite felt (GF) (hereafter referred as "hybrid GF-biocathode") was developed and evaluated in a two-chamber microbial electrolysis cells (MECs). Methane production with hybrid GF-biocathode reached 80.9mL/L at the potential of -1.4V after 24h of incubation with coulombic efficiency of 194.4%. The tests by flushing three substrates (CO2, N2 and H2-CO2 [80:20]) revealed that direct electron transfer rather than intermediate H2 contributed more to the electromethanogenesis. Cyclic voltammetry showed that GF enhanced the microbial electrocatalysis activity and reduced the cathode overpotential needed for methane production. Scanning electron microscope and fluorescence in situ hybridization analysis confirmed that the three-dimensional GF afforded the abundant space for the growth of electroactive microorganisms and promoted the electron exchange (e.g. cathode-to-cell etc.) via severing as "artificial pili". This study reveals that GF with the open structure and high conductivity has the substantial potential to upgrade electromethanogenesis efficiency.

Original languageEnglish
Pages (from-to)1146-1155
Number of pages10
JournalChemical Engineering Journal
Volume284
DOIs
Publication statusPublished - 2016 Jan 15

Bibliographical note

Funding Information:
The authors wish to thank the Japan Society for Promotion of Science (JSPS, ID No. PU 14016) and China Scholarship Council (CSC, File No. 201306890003) for partial support of this study.

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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