Sean Ashton's doctoral thesis, which he finished at the Technical University in Munich, describes the challenge of constructing a Differential Electrochemical Mass Spectrometer instrument (DEMS). DEMS combines an electrochemical cell with mass spectrometry via a membrane interface, allowing gaseous and volatile electrochemical reaction species to be monitored online. The thesis carefully introduces the fuel cell electrocatalyst development concerns before reviewing the pertinent literature on DEMS. This is followed by the presentation and discussion of the new extended design, including a...