Hydrogen production with a microbial biocathode.
This paper, for the first time, describes the development of a microbial biocathode for hydrogen production that is based on a naturally selected mixed culture of electrochemically active micro-organisms. This is achieved through a three-phase biocathode startup procedure that effectively turned an acetate- and hydrogen-oxidizing bioanode into a hydrogen-producing biocathode by reversing the polarity of the electrode. The microbial biocathode that was obtained in this way had a current density of about -1.2 A/Nm2 at a potential of -0.7 V. This was 3.6 times higher than that of a control electrode (-0.3 A/m2). Furthermore, the microbial biocathode produced about 0.63 m3 H2/m3 cathode liquid volume/day at a cathodic hydrogen efficiency of 49% during hydrogen yield tests, whereas the control electrode produced 0.08 m3 H2/m3 cathode liquid volume/day at a cathodic hydrogen efficiency of 25%. The effluent of the biocathode chamber could be used to inoculate another electrochemical cell that subsequently also developed an identical hydrogen-producing biocathode (-1.1 A/m2 at a potential of -0.7 V). Scanning electron micrographs of both microbial biocathodes showed a well-developed biofilm on the electrode surface.
Rozendal
René A
RA
Sub-Department of Environmental Technology, Wageningen University, Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
Jeremiasse
Adriaan W
AW
Hamelers
Hubertus V M
HV
Buisman
Cees J N
CJ
D001674:Bioelectric Energy Sources; D004566:Electrodes; D006859:Hydrogen / Q000378:metabolism*
D006859:Hydrogen