title: Spatially distributed current oscillations with electrochemical reactions in microfluidic flow cells.
abstract: The formation of spatiotemporal patterns is investigated by using a chemical reaction on the surface of a high-aspect-ratio metal electrode positioned in a flow channel. A partial differential equation model is formulated for nickel dissolution in sulfuric acid in a microfluidic flow channel. The model simulations predict oscillatory patterns that are spatially distributed on the electrode surface; the downstream portion of the metal surface exhibits large-amplitude, nonlinear oscillations of dissolution rates, whereas the upstream portion displays small-amplitude, harmonic oscillations with a phase delay. The features of the dynamical response can be interpreted by the dependence of local dynamics on the widely varying surface conditions and the presence of strong coupling. The patterns can be observed for both contiguous and segmented metal surfaces. The existence of spatially distributed current oscillations is confirmed in experiments with Ni electrodissolution in a microfluidic device. The results show the impact of a widely heterogeneous environment on the types of patterns of chemical reaction rates.
authors.affiliation: Department of Chemistry, Al. I. Cuza University, 11 Carol I Blvd., 700506 Iaşi (Romania); Department of Chemistry, Saint Louis University, 3501 Laclede Ave., St. Louis, MO 63103 (USA). abirzu@uaic.ro.
authors.forename: Adrian
authors.initials: A
authors.lastname: Bîrzu
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Jia
authors.forename: Varun
authors.initials: V
authors.lastname: Sankuratri
authors.forename: Yifan
authors.initials: Y
authors.lastname: Liu
authors.forename: István Z
authors.initials: IZ
authors.lastname: Kiss
keywords: electrochemistry; flow cells; kinetics; microfluidics; oscillatory dynamics