While batteries are ideal for the storage of electricity from intermittent renewable sources on a time scale from seconds to days, an alternative energy storage technology is needed to balance seasonal variations in electricity production. A promising approach is to convert electric power into a combustible fuels that can be stored in tanks for extended periods of time and ideally be transported in pipelines.


Our research focuses on the electrochemical production of hydrogen from water. Besides research on (photo-/electro-)catalysts, we also developed membranes for alkaline electrolysis to avoid mixing of hydrogen and oxygen. To study newly developed materials under realistic operating conditions, we further built a lab-scale alkaline electrolyser operating at 80 °C and 60 bar.

Fig. 1: a) Schematics of CO2 electrolysis setup. b) Scanning electron microscopy image of an electrodeposited copper catalyst for CO2 reduction. c) Analysis of reaction products. Gas phase products are identified and/or quantified by gas chromatography (GC), mass spectrometry (MS), or Fourier transform infrared spectroscopy (FTIR), liquid phase products by nuclear magnetic resonance (NMR).



Swiss Federal Office of Energy, Swiss National Science Foundation, Swiss Electric, Horizon 2020.

Selected publications

[1] W. Ju, F. Jiang, H. Ma, Z. Pan, Y.-B. Zhao, F. Pagani, D. Rentsch, J. Wang, C. Battaglia, Electrocatalytic reduction of gaseous CO2 to CO on Sn/Cu-nanofiber-based gas diffusion electrodes, Adv. Energy Mater. 2019, 1901514.

[1] W. Ju, J. Zeng, K. Bejtka, H. Ma, D. Rentsch, M. Castellino, A. Sacco, C. F. Pirri, C. Battaglia, Sn-decorated Cu for selective electrochemical CO2 conversion: precision architecture beyond composition design, ACS Appl. Energy Mater. 2019, 2, 867.

[2] S. Ardo, D. F. Rivas, M. A. Modestino, V. Schulze Greiving, F. Abdi, E. Alarcon-Llado, V. Artero, K. E. Ayers, C. Battaglia et al, Pathways to electrochemical solar-hydrogen technologies, Energy & Environ. Science,  2018, 11, 2768.

[3] W. Ju, M. V. F. Heinz, L. Pusterla, M. Hofer, B. Fumey, R. Castiglioni, M. Pagani, C. Battaglia, U. F. Vogt, Lab-scale alkaline electrolyzer for bridging material fundamentals with realistic operation, ACS Sust, Chem. Eng., 2018, 6, 4829.


Press releases
Green fuels for aviation, Empa-PSI press release, 25.2.2021 (English)