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

Abstract

A palladium composite membrane was prepared via electroless plating technique using organic-inorganic method during activation process. The ceramic support surface was modified by two TiO2-boehmite and one γ-alumina layers to avoid Pd penetration in support pores. 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 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 then the pressure exponent n was very close to 1. According to linear relationship of Arrhenius plot, the activation energy Ea of Pd membrane was calculated to be 22.54 kJ/mol. H2 permeance kept over 0.023 mol/m2s and the separation factor of H2/Ar over infinite at 773 K for 240 h, confirming high potential of the prepared membrane in H2 purification at high temperatures.