Preparation of a Pd composite membrane via an organic-inorganic activation method in the electroless plating technique

A palladium composite membrane was prepared via an electroless plating technique using the organic-inorganic method during the activation process. The ceramic support surface was modified by two TiO2-boehmite and one γ-alumina layers to avoid Pd penetration in the support pores. A thin and defect-free Pd composite membrane was obtained by creating a relative smoothness on the ceramic support and using Pd nanoparticles in the activated layer. The resulting membrane showed an infinite selectivity for H2/Ar with an H2 flux in the range of 0.005-0.035 mol/m2s depending on operating conditions. The hydrogen flux was linearly proportional to the pressure difference across the membrane at different temperatures and the pressure exponent n was very close to 1. According to the linear relationship of Arrhenius plot, the activation energy Ea of the Pd membrane was calculated to be 22.54 kJ/mol. H2 permeance was kept over 0.023 mol/m2s and the separation factor of H2/Ar was over infinite at 773 K for 240 h, confirming a high potential of the prepared membrane in H2 purification at high temperatures.