Hydrogen separation using polybenzimidazole membrane with palladium nanoparticles stabilized by polyvinylpyrrolidone

Abstract

An innovation in hydrogen (H2) selective membrane holds the substantial key of H2 economy. Polymers are the most practical and economical material for membrane fabrication, but their application in H2 separation is always constrained within the selectivity-permeability “trade-off” boundary. The expensive palladium (Pd) thin films offer higher selectivity by facilitating the dissociation, diffusion and re-association of H2 gas. This work reports on the incorporation of Pd nanoparticles into polybenzimidazole (PBI) membranes to surpass the mentioned limitations. Pd nanoparticles were synthesized and stabilized in the inversed microemulsion of polyvinylpyrrolidone (PVP) prior to blending. The X-ray diffraction and energy dispersive X-ray results proved the presence of Pd nanoparticles blended into PBI membrane with dense structure. The agglomerated and the stabilized Pd nanoparticles PBI matrix behaved very differently in H2 adsorption at the rising temperature as shown in temperature-programmed reduction results. The ideal H2/CO2 selectivity of PBI membrane with 1 wt% of Pd nanoparticles was improved by 49% compared to the PBI membrane at 150°C. This membrane surpassed the upper bound Robeson plot at 300°C (ideal H2/CO2 selectivity of 83.57; H2 permeability of 151.73 Barrer) and the H2 permeation could be correlated with Van't Hoff-Arrhenius equation.