(401w) Sorption Enhanced Mixed Matrix Materials Comprising Palladium Nanoparticles and Polybenzimidazole for H2/CO2 Separation

Authors: 
Zhu, L., University at Buffalo, The State University of New York
Yin, D., University at Buffalo, The State University of New York
Konda, S., University at Buffalo, The State University of New York
Swihart, M. T., University at Buffalo, The State University of New York
Lin, H., University at Buffalo, The State University of New York
Polymeric membranes have been widely explored for energy-efficient and low-cost CO2 capture and H2 purification in the integrated gasification combined cycle (IGCC) processes. Conventional approaches are focused on designing rigid polymers with strong size sieving ability achieving high H2/CO2 diffusivity, such as poly[2,2’-(m-phenylene)-5,5’-bisbenzimidazole] (PBI). In contrast, we investigate mixed matrix materials (MMMs) containing PBI and palladium (Pd) nanoparticles, which have strong affinity towards H2 and thus exhibit extremely high H2/CO2 solubility selectivity. Pd nanoparticles with uniform diameters of 6 - 8 nm are prepared via hot-injection approaches, which show H2/CO2 solubility selectivity of 840, compared with < 0.1 for typical polymers. The effect of Pd loading (0 - 70 wt%) and temperature on the pure- and mixed-gas H2/CO2 separation properties is thoroughly evaluated. The loading of Pd nanoparticles dramatically increases H2 solubility and H2/CO2 solubility selectivity, resulting in a significant increase in H2 permeability and H2/CO2 selectivity at temperatures of 100 - 200 oC. For example, adding 70 wt% Pd in PBI increases H2 permeability from 25 to 70 Barrers, and H2/CO2 selectivity from 13 to 29 at 150 oC. Such performance is above the upper bound of the Robeson’s plot for H2/CO2 separation, demonstrating their potential for industrial H2/CO2 separation. This presentation will also examine morphology of the MMMs and describe a model to elucidate the relationship of the structure and H2 transport properties in these sorption enhanced MMMs.