For the measurement of catalysts in operando mode, that is directly in the fuel cell during operation at real pressures and potentials, by XAS (X-ray absorption spectroscopy) and WAXS (wide angle x-ray scattering) methods at the Elettra synchrotron in Trieste, a special fuel was designed and tested as a fuel cell adapted for the passage of beam of radiation.
The operando fuel cell were made from stainless steel monopolar plates with single serpentine flowfields of 22 x 24 mm. Active are of the FC was 5 cm2. The plates were equipped with 6mm OD - 1/8" NPT compression connectors for connecting a gas handling system. The beam inlet monopolar plate exhibited 0,5x1 mm window placed in the plate center at the bottom of the flow field groove, the exit window had a conical shape suitable for collecting scattered beam at wide angle (WACS). The small holes of 0,5 mm were also made in the transport porous layers. The cell was heated by embedded heating cartridges. The precise ceramic rods were used for perfect alignment of inlet and outlet beam holes. The monopolar plates served as collectors and were connected to the potentiostat.