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dc.contributor.authorYe, Yaoli
dc.contributor.authorLogan, Bruce
dc.date.accessioned2018-02-01T08:12:00Z
dc.date.available2018-02-01T08:12:00Z
dc.date.issued2018-01-11
dc.identifier.citationYe Y, Logan BE (2018) The importance of OH − transport through anion exchange membrane in microbial electrolysis cells. International Journal of Hydrogen Energy. Available: http://dx.doi.org/10.1016/j.ijhydene.2017.12.074.
dc.identifier.issn0360-3199
dc.identifier.doi10.1016/j.ijhydene.2017.12.074
dc.identifier.urihttp://hdl.handle.net/10754/626998
dc.description.abstractIn two-chamber microbial electrolysis cells (MECs) with anion exchange membranes (AEMs), a phosphate buffer solution (PBS) is typically used to avoid increases in catholyte pH as Nernst equation calculations indicate that high pHs adversely impact electrochemical performance. However, ion transport between the chambers will also impact performance, which is a factor not included in those calculations. To separate the impacts of pH and ion transport on MEC performance, a high molecular weight polymer buffer (PoB), which was retained in the catholyte due to its low AEM transport and cationic charge, was compared to PBS in MECs and abiotic electrochemical half cells (EHCs). In MECs, catholyte pH control was less important than ion transport. MEC tests using the PoB catholyte, which had a higher buffer capacity and thus maintained a lower catholye pH (<8), resulted in a 50% lower hydrogen production rate (HPR) than that obtained using PBS (HPR = 0.7 m3-H2 m−3 d−1) where the catholyte rapidly increased to pH = 12. The main reason for the decreased performance using PoB was a lack of hydroxide ion transfer into the anolyte to balance pH. The anolyte pH in MECs rapidly decreased to 5.8 due to a lack of hydroxide ion transport, which inhibited current generation by the anode, whereas the pH was maintained at 6.8 using PBS. In abiotic tests in ECHs, where the cathode potential was set at −1.2 V, the HPR was 133% higher using PoB than PBS due to catholyte pH control, as the anolyte pH was not a factor in the performance. These results show that maintaining charge transfer to control anolyte pH is more important than obtaining a more neutral pH catholyte.
dc.description.sponsorshipThis work was supported by Award OSR-2015-SEED-2450-01 from the King Abdullah University of Science and Technology (KAUST).
dc.publisherElsevier BV
dc.subjectHydrogen
dc.subjectMicrobial electrolysis cell
dc.subjectAnion exchange membrane
dc.subjectAnolyte pH
dc.subjectBuffer retention
dc.subjectPolymeric buffer
dc.titleThe importance of OH − transport through anion exchange membrane in microbial electrolysis cells
dc.typeArticle
dc.identifier.journalInternational Journal of Hydrogen Energy
dc.contributor.institutionDepartment of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
kaust.grant.numberOSR-2015-SEED-2450-01
dc.date.published-online2018-01-11
dc.date.published-print2018-02


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