Preparation and characterization of Cu/YSZ cathode for high-temperature electrolysis

Abstract

The Cu/Y 2 O 3 -stabilized ZrO 2 (YSZ) composite was successfully fabricated by high-energy ball-milling method for possible use as a cathode material in high-temperature electrolysis (HTE) cell. Thus, the fabricated Cu/YSZ composite was characterized using various analytical tools such as XRD, SEM, TEM and laser diffraction and scattering method. The Cu/YSZ cermet was observed to consist of crystalline Cu and YSZ in sub-micron scale and evenly distributed without forming aggregates. Electrical conductivity of ball-milled and sintered Cu/YSZ cermet pellet was measured by 4-probe technique and compared with that of conventional Ni/YSZ cermets. The effect of composites composition on the electrical conductivity was also investigated and the marked increase in electrical conductivity for Cu/YSZ over Ni/YSZ was attributed to more open micro-structural morphology of Cu/YSZ and higher electrical conductivity of copper, which explains higher hydrogen production rate for HTE cell with Cu/YSZ cathode compared with HTE cell with Ni/YSZ cathode during actual HTE at 800°C.