Development of Electrode Supported Proton Conducting Solid Oxide Cells and their Evaluation as Electrochemical Hydrogen Pumps

Protonic ceramic solid oxide cells (P-SOCs) have gained widespread attention due to their potential to operate at intermediate temperature range which is not only beneficial in terms of material stability but also offers unique possibilities from thermodynamic point of view to realize series of reactions. For instance, they are ideal for the production of synthetic fuels by hydrogenation of carbon dioxide and nitrogen, upgradation of hydrocarbons or dehydrogenation reactions. However, the development of P-SOC is quite challenging as it requires a multi-front optimization in terms of material synthesis and fabrication procedures. Herein, we report in detail the way to overcome various fabrication challenges for the development of efficient and robust electrode supported P-SOCs (Ni-BCZY/BCZY/Ni-BCZY) based on BaCe0.2Zr0.7Y0.1O3-δ (BCZY271) electrolyte. We have examined the effect of pore formers on the porosity of the Ni-BCZY support electrode, various electrolyte deposition techniques (spray, spin and vacuum assisted) and thermal treatment for developing robust and flat half cells. The half-cells containing a thin (10-12µm) pinhole free electrolyte layer are completed by screen printed Ni-BCZY electrode and evaluated as a hydrogen pump. The obtained current density ranges from 150 to 525 mA.cm-2 at 1 V and operating temperature 350 to 450oC. The faradaic efficiency of the P-SOCs as well as their stability were evaluated