Laminar flow-based biofuel cells: Independent control of pH at the anode and cathode for optimal electrode activity

Seong Kee Yoon, Michael Mitchell, Ranga S. Jayashree, Paul J A Kenis

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Recently, many advances have been made in the development of biofuel cells [1]. One of the major advances has been the use of electrocatalysts that increase the rate of electron transfer from an enzyme or redox mediator to the surface of an electrode. One recent report includes the electropolymerization of methylene green at an electrode surface to form an electrocatalyst to mediate electron transfer from NADH to a bioanode [2]. The catalysis of NADH oxidation to regenerate NAD+ is an important reaction, as NAD+ is an important cofactor for many enzymes, including alcohol dehydrogenase and aldehyde dehydrogenase. These enzymes can be used for the electrooxidation of ethanol or methanol at the anode of a biofuel cell [2]. Recently, we have developed membraneless microfluidic fuel cells that exploit laminar flow at the microscale to separate the fuel and oxidant streams [3]. Because the streams mix only by diffusion, fuel and oxidant streams of different pHs can be used such that the anode and cathode both operate at their optimal pH. One issue with biofuel cells, however, is the fact that different enzymes have optimal activity at different pHs. Using a fixed pH electrolyte may maximize the enzyme activity at one electrode while resulting in poor enzyme activity (or even denaturing of the enzyme) at the electrode. Ideally, one would like to operate the anode and cathodes at different pHs such that both electrodes could operate optimally. We will show our work in designing and operating laminar flow biofuel cells that are run using alcohol and oxygen, with buffered alcohol solution (pH∼7) and aqueous sulfuric acid solution (pH∼0) as the anolyte and catholyte, respectively.

Original languageEnglish (US)
Title of host publication05AIChE
Subtitle of host publication2005 AIChE Annual Meeting and Fall Showcase, Conference Proceedings
Number of pages1
StatePublished - 2005
Externally publishedYes
Event05AIChE: 2005 AIChE Annual Meeting and Fall Showcase - Cincinnati, OH, United States
Duration: Oct 30 2005Nov 4 2005


Other05AIChE: 2005 AIChE Annual Meeting and Fall Showcase
Country/TerritoryUnited States
CityCincinnati, OH

ASJC Scopus subject areas

  • General Engineering


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