Abstract: Hydrogen permeation ability of Ni-BaCe_0.9Y_0.1O_3-δ(Ni-BCY)cermet with different Ni volume ratios were investigated at intermediate temperatures (600--750℃). The experimental results show that proton-electronic mixed conductors are formed when Ni volume ratio is up to 25%, and the hydrogen permeation rate reaches the highest when Ni volume ratio is 30%. The hydrogen permeation measurement results of Ni-BCY(40/60) cermet with different thicknesses indicate that the bulk diffusion controls hydrogen permeation when thicknesses of samples are above 0.6mm, however, as reducing sample thickness to 0.36mm or less hydrogen permeation is controlled by surface exchange process.

Key words: Ni-BaCe_0.9Y_0.1O_3-δ cermet, volume ratio, hydrogen separation