Journal article
Accelerated H-2 Evolution during Microbial Electrosynthesis with Sporomusa ovata
Microbial electrosynthesis (MES) is a process where bacteria acquire electrons from a cathode to convert CO2 into multicarbon compounds or methane. In MES with Sporomusa ovata as the microbial catalyst, cathode potential has often been used as a benchmark to determine whether electron uptake is hydrogen-dependent.
In this study, H-2 was detected by a microsensor in proximity to the cathode. With a sterile fresh medium, H-2 was produced at a potential of -700 mV versus Ag/AgCl, whereas H-2 was detected at -500 mV versus Ag/AgCl with cell-free spent medium from a S. ovata culture. Furthermore, H-2 evolution rates were increased with potentials lower than -500 mV in the presence of cell-free spent medium in the cathode chamber.
Nickel and cobalt were detected at the cathode surface after exposure to the spent medium, suggesting a possible participation of these catalytic metals in the observed faster hydrogen evolution. The results presented here show that S. ovata-induced alterations of the cathodic electrolytes of a MES reactor reduced the electrical energy required for hydrogen evolution.
These observations also indicated that, even at higher cathode potentials, at least a part of the electrons coming from the electrode are transferred to S. ovata via H-2 during MES.
Language: | English |
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Publisher: | MDPI AG |
Year: | 2019 |
Pages: | 166 |
ISSN: | 20734344 |
Types: | Journal article |
DOI: | 10.3390/catal9020166 |
ORCIDs: | Zhang, Tian |
bacteria biocatalysis biohydrogen electrochemistry industrial biotechnology process development