A Cyclone Flow Cell for Quantitative Analysis of Kinetics at Porous Electrodes by Differential Electrochemical Mass Spectrometry
By F. Kubannek and U. Krewer
Published in Electrochimica Acta
NULL
2016
Abstract
In this work the scope of differential electrochemical mass spectrometry (DEMS) is extended towards quantitatively identifying kinetics of electrochemical reactions in porous electrodes by dynamic measurements. The method is demonstrated by analyzing the kinetics of \CO\ oxidation on a carbon supported Pt/Ru catalyst using a cyclone flow \DEMS\ cell, which allows online studies of porous electrodes. The cyclone flow cell generates a rotating flow field above the stationary electrode. Experimentally validated \CFD\ simulations show that the constructed cell features a homogeneous concentration boundary layer over approximately 75% of the electrode surface area, and that the diffusion limited current density is proportional to flow rate to the power of two third, which is characteristic for turbulent flows. Calibration experiments are performed, and a physical model including mass transfer and reactions inside the porous electrode as well as information about the concentration boundary layer from the \CFD\ results is set up. By matching simulation results and experimental data for \CO\ oxidation, kinetic parameters are determined. With DEMS, not only current and potential but also the \CO2\ production rate can be observed with a high time resolution which allows to conduct quantitative macrokinetic analysis and to identify parameters quite reliably with a low number of dynamic experiments.
Microsoft is Ending Support for Windows 7
Microsoft will discontinue support for Windows 7 on January 14, 2020 which means Gamry will also be discontinuing support for Windows 7. If you are upgrading to Windows 10, like many companies and institutions, you need to be running Version 7 of our s oftware . Please note that only USB and Ethernet-based instruments can run in Version 7. Eligible users can download the latest version of our software through our online Client Portal .
If you haven't already registered your instrument, you can do so through the Client Portal .
Please email Technical Support if you have any questions regarding this transition. Please be sure to include your instrument model and serial number when contacting us.