Electrochemical study of Pd-coated perovskite anodes in sulfur-based hybrid cycle

Sulfur-based hybrid cycle (SHC) process has been attracted much attention as a mass production process of hydrogen, which consists of an electrolysis step and a thermal decomposition one. To achieve high efficiency for hydrogen evolution, a development of the electrode materials with high corrosion resistance, high electrical conductivity and low anodic potential is a key technology for the electrolysis in H₂SO₄ solutions. In our previous study, we found that Ti-based pyrochlores and perovskites showed high corrosion resistance in a 50 wt.%H₂SO₄ solution at the operation temperature and succeeded that the materials had good electrical conductivity up to 1 S/cm by rare earth metal, Nb- or Ta-doping, A-site deficient compositions and the reducing treatment, while maintaining the high corrosion resistance. In this paper, we measured the stability of electrical conductivity for the titanium oxide in the 50 wt.% H₂SO₄ solution at the operation temperature. Additionally, the application of Pd coating technique on the Tadoped titanium oxide was evaluated using electroless deposition technique, in order to provide some catalytic properties to the materials.