title: Gastight Hydrodynamic Electrochemistry: Design for a Hermetically Sealed Rotating Disk Electrode Cell.
abstract: Rotating disk electrodes (RDEs) are widely used in electrochemical characterization to analyze the mechanisms of various electrocatalytic reactions. RDE experiments often make use of or require collection and quantification of gaseous products. The combination of rotating parts and gaseous analytes makes the design of RDE cells that allow for headspace analysis challenging due to gas leaks at the interface of the cell body and the rotator. In this manuscript we describe a new, hermetically sealed electrochemical cell that allows for electrode rotation while simultaneously providing a gastight environment. Electrode rotation in this new cell design is controlled by magnetically coupling the working electrode to a rotating magnetic driver. Calibration of the RDE using a tachometer shows that the rotation speed of the electrode is the same as that of the magnetic driver. To validate the performance of this cell for hydrodynamic measurements, limiting currents from the reduction of a potassium ferrocyanide (K4[Fe(CN)6]·3H2O) were measured and shown to compare favorably with calculated values from the Levich equation and with data obtained using more typical, nongastight RDE cells. Faradaic efficiencies of ∼95% were measured in the gas phase for oxygen evolution in alkaline media at an Inconel 625 alloy electrocatalyst during rotation at 1600 rpm. These data verify that a gastight environment is maintained even during rotation.
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Suho
authors.identifier: 0000-0002-8119-3902
authors.initials: S
authors.lastname: Jung
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Ruud
authors.initials: R
authors.lastname: Kortlever
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Ryan J R
authors.initials: RJ
authors.lastname: Jones
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Lichterman
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Theodor
authors.identifier: 0000-0002-9692-7614
authors.initials: T
authors.lastname: Agapie
authors.affiliation: Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48104, United States.
authors.forename: Charles C L
authors.identifier: 0000-0001-9039-7192
authors.initials: CC
authors.lastname: McCrory
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Jonas C
authors.initials: JC
authors.lastname: Peters