1. Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Wilhelm-Runge-Str. 10, 89081 Ulm, Germany
2. Helmholtz Institute Ulm (HIU), Helmholtzstr. 11, 89081 Ulm, Germany
3. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
4. Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
5. Department of Electrochemistry, University of Ulm, Albert-Einstein-Allee 47, 89081 Ulm, Germany