March 2019

Oxygen production is of paramount importance for steel and chemical industry. Nowadays it is widely carried out in large scale using cryogenic distillation processes, which need to be volume and energy intensive in order to be profitable and viable. An average oxygen production plant produces 4000 to 10000 tons/day using 200 kWh/tons. The implementation of oxide conductors opened the way for oxygen permeation ceramic materials for more energy sustainable processes. The basic requirements are high electronic and ionic conductivities, thermal and chemical stability. The main preparation route for these materials is using high amounts of noble metals such as Pd or Pt (up to 50% V/V) to grant the needed electronic conductivity and this makes the large-scale application economically not viable. A possible solution could be to minimize the amount of the electron conducting material in nanostructured composite materials. Several nano-structured porous YSZ thin films homogeneously coated with 12 nm of Pt using atomic layer deposition were prepared. In order to assess the interface contribution on the defect concentration and the catalytic effect of the Pt presence on the oxygen redox reactions, a series of multilayered YSZ-Pt-YSZ samples were prepared. The as prepared materials were structurally characterized using grazing incidence X-ray diffraction (GIXRD) and time of flight secondary ions mass spectrometry (TOF-SIMS). The polycrystalline structures of both Pt and YSZ were confirmed as well as the expected nanostructure. Electrochemical impedance spectroscopy (EIS) measurements are performed to correlate the structural and morphologic features of the materials with the ionic transport and in particular to elucidate the influence of the interfaces on the transport properties. (Picture submitted by Michele Bastianello.)