Bambalaza, Sonwabo ELangmi, HWMokaya, RMusyoka, Nicholas MKhotseng, LE2021-04-102021-04-102020-12Bambalaza, S.E., Langmi, H., Mokaya, R., Musyoka, N.M. & Khotseng, L. 2020. Co-pelletization of a zirconium-based metalorganic framework (UiO-66) with polymer nanofibers for improved useable capacity in hydrogen storage. <i>International Journal of Hydrogen Energy, 46(12).</i> http://hdl.handle.net/10204/119690360-31991879-3487https://doi.org/10.1016/j.ijhydene.2020.12.049https://www.sciencedirect.com/science/article/pii/S0360319920345833http://hdl.handle.net/10204/11969We report on a concept of co-pelletization using mechanically robust hydroxylated UiO-66 to develop a metal-organic framework (MOF) monolith that contains 5 wt% electrospun polymer nanofibers, and consists of an architecture with alternating layers of MOF and nanofiber mats. The polymers of choice were the microporous Polymer of Intrinsic Microporosity (PIM-1) and non-porous polyacrylonitrile (PAN). Co-pelletized UiO-66/PIM-1 and UiO-66/PAN monoliths retain no less than 85% of the porosity obtained in pristine powder and pelletized UiO-66. The composition of the pore size distribution in co-pelletized UiO-66/PIM-1 and UiO-66/PAN monoliths is significantly different to that of pristine UiO-66 forms, with pristine UiO-66 forms showing 90% of the pore apertures in the micropore region and both UiO-66/nanofiber monoliths showing a composite micro-mesoporous pore size distribution. The co-pelletized UiO-66/nanofiber monoliths obtained improved useable H2 capacities in comparison to pristine UiO-66 forms, under isothermal pressure swing conditions. The UiO-66/PIM-1 monolith constitutes the highest gravimetric (and volumetric) useable capacities at 2.3 wt% (32 g L−1) in comparison to 1.8 wt% (12 g L−1) and 1.9 wt% (29 g L−1) obtainable in pristine UiO-66 powder and UiO-66 pellet, respectively. The co-pelletized UiO-66/PAN monolith, however, shows a significantly reduced surface area by up to 50% less in comparison to pristine UiO-66, but its pore volume only 13% less in comparison to pristine UiO-66. As a result, total gravimetric H2 capacity of the co-pelletized UiO-66/PAN monolith is 50% less in comparison to that of pristine UiO-66, but crucially the useable volumetric H2 capacity is 50% higher for the UiO-66/PAN monolith in comparison to pristine UiO-66 powder. The co-pelletization strategy provides a simple method for generating hierarchical porosity into an initially highly microporous MOF without changing the structure of the MOF through complex chemical modifications. The UiO-66/nanofiber monoliths offer improvements to the typically low H2 useable capacities in highly microporous MOFs, and open new opportunities towards achieving system-level H2 storage targets.AbstractenCo-pelletizationHydrogen useable capacityHierarchical porosityMetal-organic frameworkUiO-66ArticleBambalaza, S. E., Langmi, H., Mokaya, R., Musyoka, N. M., & Khotseng, L. (2020). Co-pelletization of a zirconium-based metalorganic framework (UiO-66) with polymer nanofibers for improved useable capacity in hydrogen storage. <i>International Journal of Hydrogen Energy, 46(12)</i>, http://hdl.handle.net/10204/11969Bambalaza, Sonwabo E, HW Langmi, R Mokaya, Nicholas M Musyoka, and LE Khotseng "Co-pelletization of a zirconium-based metalorganic framework (UiO-66) with polymer nanofibers for improved useable capacity in hydrogen storage." <i>International Journal of Hydrogen Energy, 46(12)</i> (2020) http://hdl.handle.net/10204/11969Bambalaza SE, Langmi H, Mokaya R, Musyoka NM, Khotseng L. Co-pelletization of a zirconium-based metalorganic framework (UiO-66) with polymer nanofibers for improved useable capacity in hydrogen storage. International Journal of Hydrogen Energy, 46(12). 2020; http://hdl.handle.net/10204/11969.TY - Article AU - Bambalaza, Sonwabo E AU - Langmi, HW AU - Mokaya, R AU - Musyoka, Nicholas M AU - Khotseng, LE AB - We report on a concept of co-pelletization using mechanically robust hydroxylated UiO-66 to develop a metal-organic framework (MOF) monolith that contains 5 wt% electrospun polymer nanofibers, and consists of an architecture with alternating layers of MOF and nanofiber mats. The polymers of choice were the microporous Polymer of Intrinsic Microporosity (PIM-1) and non-porous polyacrylonitrile (PAN). Co-pelletized UiO-66/PIM-1 and UiO-66/PAN monoliths retain no less than 85% of the porosity obtained in pristine powder and pelletized UiO-66. The composition of the pore size distribution in co-pelletized UiO-66/PIM-1 and UiO-66/PAN monoliths is significantly different to that of pristine UiO-66 forms, with pristine UiO-66 forms showing 90% of the pore apertures in the micropore region and both UiO-66/nanofiber monoliths showing a composite micro-mesoporous pore size distribution. The co-pelletized UiO-66/nanofiber monoliths obtained improved useable H2 capacities in comparison to pristine UiO-66 forms, under isothermal pressure swing conditions. The UiO-66/PIM-1 monolith constitutes the highest gravimetric (and volumetric) useable capacities at 2.3 wt% (32 g L−1) in comparison to 1.8 wt% (12 g L−1) and 1.9 wt% (29 g L−1) obtainable in pristine UiO-66 powder and UiO-66 pellet, respectively. The co-pelletized UiO-66/PAN monolith, however, shows a significantly reduced surface area by up to 50% less in comparison to pristine UiO-66, but its pore volume only 13% less in comparison to pristine UiO-66. As a result, total gravimetric H2 capacity of the co-pelletized UiO-66/PAN monolith is 50% less in comparison to that of pristine UiO-66, but crucially the useable volumetric H2 capacity is 50% higher for the UiO-66/PAN monolith in comparison to pristine UiO-66 powder. The co-pelletization strategy provides a simple method for generating hierarchical porosity into an initially highly microporous MOF without changing the structure of the MOF through complex chemical modifications. The UiO-66/nanofiber monoliths offer improvements to the typically low H2 useable capacities in highly microporous MOFs, and open new opportunities towards achieving system-level H2 storage targets. DA - 2020-12 DB - ResearchSpace DP - CSIR J1 - International Journal of Hydrogen Energy, 46(12) KW - Co-pelletization KW - Hydrogen useable capacity KW - Hierarchical porosity KW - Metal-organic framework KW - UiO-66 LK - https://researchspace.csir.co.za PY - 2020 SM - 0360-3199 SM - 1879-3487 T1 - Co-pelletization of a zirconium-based metalorganic framework (UiO-66) with polymer nanofibers for improved useable capacity in hydrogen storage TI - Co-pelletization of a zirconium-based metalorganic framework (UiO-66) with polymer nanofibers for improved useable capacity in hydrogen storage UR - http://hdl.handle.net/10204/11969 ER -24265