Enzymatic oxygen reduction under quiescent conditions — the importance of convection

• Published in: Electrochemistry communications 2013-09, Vol.34, p.94-97
• Main Authors: Urban, J., Zloczewska, A., Stryczniewicz, W., Jönsson-Niedziolka, M.
• Format: Article
• Language: English
• Subjects: Bilirubin oxidase; Bioelectrocatalysis; Biological and medical sciences; Convection; Cyclic voltammetry; Electrochemistry; Fundamental and applied biological sciences. Psychology; Molecular biophysics; Oxygen reduction; Physical chemistry in biology; Simulation
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2013.05.030

Over the last decade the current densities reported from biocathodes for oxygen reduction have increased dramatically. However, many reports in the literature of measurements performed under quiescent conditions appear to show current densities above the mass transport limit. We measure the native convection of electrolyte in an electrochemical cell and show that by including this movement in computer simulations experimental data can be reproduced. Thus we clearly show that convection plays an important role when interpreting results from slow scan cyclic voltammetry and that care must be taken not to conflate electrode performance with hydrodynamic effects. [Display omitted] •We have made simulations of enzyme catalysed oxygen reduction using COMSOL.•Results under quiescent conditions cannot be recreated unless convection is included•We have measured the convection in an electrochemical cell using PIV.•By including convection in our simulation experimental data can be recreated.•One must not underestimate the importance of convection under nominally quiescent conditions.