May 2013

The workgroup of Prof. Janek has received a high vacuum chamber for electrochemical mass spectrometry on solid cells (Solid electrochemical mass spectrometry (SEMS)) as a loan from the workgroup of Dr. Wolfgang Harbich (EPFL Lausanne, Switzerland). This set-up provides coupling of electrochemical and mass spectrometric techniques to obtain a deeper insight into the processes of electrochemical solid cells. The left side of the picture shows schematically the core piece of the high vacuum chamber. It consists of a heatable copper reactor in which the electrochemical cell is placed. Reaction gases are fed by capillaries and analyzed by a mass spectrometer equipped with a cylindrical tube (sniffer). By this set-up electrochemical and catalytic processes of platinum and silver electrodes on solid oxygen ion conductors are investigated. The right side of the picture shows the mass spectrometry signal of the oxygen evolution during anodic polarization (I = 10 µA) of a silver electrode at different temperatures. The different characteristics at different temperatures suggesting different mechanisms of oxygen storage and evolution can be clearly seen. (Picture submitted by Christoph Bachmann)