Journal article
Oxygen reduction kinetics on graphite cathodes in sediment microbial fuel cells
Physical chemistry chemical physics : PCCP, Vol.13(48), pp.21573-21584
12/28/2011
Handle:
https://hdl.handle.net/2376/111989
PMCID: PMC3551589
PMID: 22052235
Abstract
Sediment microbial fuel cells (SMFCs) have been used as renewable power sources for sensors in fresh and ocean waters. Organic compounds at the anode drive anodic reactions, while oxygen drives cathodic reactions. An understanding of oxygen reduction kinetics and the factors that determine graphite cathode performance is needed to predict cathodic current and potential losses, and eventually to estimate the power production of SMFCs. Our goals were to (1) experimentally quantify the dependence of oxygen reduction kinetics on temperature, electrode potential, and dissolved oxygen concentration for the graphite cathodes of SMFCs and (2) develop a mechanistic model. To accomplish this, we monitored current on polarized cathodes in river and ocean SMFCs. We found that (1) after oxygen reduction is initiated, the current density is linearly dependent on polarization potential for both SMFC types; (2) current density magnitude increases linearly with temperature in river SMFCs but remains constant with temperature in ocean SMFCs; (3) the standard heterogeneous rate constant controls the current density temperature dependence; (4) river and ocean SMFC graphite cathodes have large potential losses, estimated by the model to be 470 mV and 614 mV, respectively; and (5) the electrochemical potential available at the cathode is the primary factor controlling reduction kinetic rates. The mechanistic model based on thermodynamic and electrochemical principles successfully fit and predicted the data. The data, experimental system, and model can be used in future studies to guide SMFC design and deployment, assess SMFC current production, test cathode material performance, and predict cathode contamination.
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Details
- Title
- Oxygen reduction kinetics on graphite cathodes in sediment microbial fuel cells
- Creators
- Ryan Renslow - The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, 118 Dana Hall Spokane St. P.O. Box 642710, Pullman, WA 99164-2710, USAConrad DonovanMatthew ShimJerome BabautaSrilekha NannapaneniJames SchenkHaluk Beyenal
- Publication Details
- Physical chemistry chemical physics : PCCP, Vol.13(48), pp.21573-21584
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Publisher
- England
- Grant note
- T32 GM008336 / NIGMS NIH HHS T32-GM008336 / NIGMS NIH HHS
- Identifiers
- 99900547652001842
- Language
- English
- Resource Type
- Journal article