1. Department of Space, Earth and Environment, Division of Energy Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
2. Department of Physics, Division of Chemical Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
3. Department of Applied Physics and Electronics, Thermochemical Energy Conversion Laboratory, Umeå University, SE-901 87 Umeå, Sweden