Porous coordination pillared layer networks: Hysteretic gas adsorption and functionalization for superior CO2 uptake

dc.contributor.advisor Hernández Maldonado, Arturo J. Riascos Rodríguez, Karina College of Engineering en_US
dc.contributor.committee Briano, Julio G.
dc.contributor.committee Martínez Iñesta, María M.
dc.contributor.committee Suleiman Rosado, David
dc.contributor.department Department of Chemical Engineering en_US
dc.contributor.representative Lorenzo, Edgardo 2020-10-24T22:14:16Z 2020-10-24T22:14:16Z 2020-02-03
dc.description.abstract Porous coordination polymers (PCPs) are crystals holding pore sizes and shapes with tremendous capabilities for carbon capture based on adsorption. Coordination pillared layer networks, with copper as central node, Cu2+-CPL-n, are PCPs with considerable potential for CO2 adsorption, showing stability, good performance for gas storage and delivery, and an intriguing hysteretic adsorption found related to the maximum gas loading. In this work, the hysteretic behavior of a selected set of CPL-n materials upon CO2 loading was addressed through adsorption and concomitant structural variation studies. These observations showed foundations to associate structural long-range distortions, and flexible-responsiveness, to interactions induced by the adsorbate. In situ CO2 adsorption and powder X-ray diffraction (XRD) measurements at room temperature, onto Cu2(pzdc)2(bpy), up to 7 bar, indicated changes in the unit cell volume. The onset of the adsorption hysteresis corresponded to a full occupancy of the pore volume, at CO2 partial pressures above 2 bar. Further assays were performed to functionalize CPL-n materials and to improve the adsorbate-adsorbent interactions, decorating prone functional groups of ligands by an alkaline metal. Cu(pzdc)(pia), which contains amide functional groups, was used to test a post-synthesis lithiation rationale. Synchrotron powder X-ray diffraction (XRD) results allowed structural elucidations to corroborate micro porosity after functionalization. CO2 adsorption up to 7 bar at room temperature showed a concave up isotherm shape with significant hysteresis upon desorption, which suggests structural variations consequent to different or stronger adsorption sites along the pores. Results from elemental, thermal gravimetric and crystal refinement analyses indicated that the lithium content is ca. 3 Li per asymmetric unit. Raman scattering shifts suggested Li positions near the amide and nitrogen pyridyl groups of pia ligand. In situ XRD and CO2 adsorption tests performed at pressures up to 50 bar and ambient temperature substantiated the structural changes anticipated by hysteresis. en_US
dc.description.abstract Los polímeros de coordinación porosos (PCPs) son cristales con poros de tamaño y forma con tremenda capacidad para capturar carbono mediante adsorción. Las redes de coordinación por lozas pilarizadas, con cobre como nodo central, Cu2+-CPL-n, son PCPs con potencial de adsorción de CO2 considerable, mostrando estabilidad, buen desempeño para almacenamiento y suministro del gas, y una intrigante adsorción histerética relacionada a la carga máxima de gas. En este trabajo, el comportamiento histerético al cargar CO2 en materiales CPL-n se abordó mediante estudios de adsorción y variaciones estructurales concomitantes. Dichas observaciones sentaron bases para asociar distorsiones de rango largo y flexibilidad, con interacciones inducidas por el adsorbato. Mediciones in situ de adsorción de CO2 y difracción de rayos-X (XRD), sobre Cu2(pzdc)2(bpy), a temperatura ambiente y hasta 7 bar, indicaron cambios en el volumen de celda unitaria. El comienzo de la histéresis ocurrió con una ocupación completa del volumen de poro, a presiones parciales superiores a 2 bar. Se realizaron ensayos adicionales para funcionalizar materiales tipo CPL-n y mejorar las interacciones adsorbato-adsorbente, decorando grupos funcionales propensos de los ligandos usando un metal alcalino. Cu(pzdc)(pia), con grupos funcionales amido, se usó en pruebas de litiación post síntesis. Resultados sincrotrón-XRD permitieron elucidaciones estructurales, corroborando la microporosidad luego de funcionalización. La adsorción de CO2 hasta 7 bar, a temperatura ambiente, mostró una isoterma cóncava hacia arriba con histéresis significativa, sugiriendo cambios estructurales por sitios de adsorción diferentes o más fuertes en los poros. Análisis elementales, termo gravimétricos y de refinamiento de cristal indicaron la incorporación de litio como ca. 3 Li por unidad asimétrica. Desplazamientos en dispersión Raman sugirieron posiciones de Li cerca a grupos amido y nitrógeno del piridil de los ligandos pia. Pruebas in situ de XRD y de adsorción de CO2 hasta 50 bar y temperatura ambiente mostraron los cambios estructurales anticipados por la histéresis. en_US
dc.description.graduationSemester Spring en_US
dc.description.graduationYear 2020 en_US
dc.description.sponsorship I thankfully acknowledge the support from the Puerto Rico Institute for Functional Materials Graduate Fellowship Program under the NSF Award No. EPS-1002410 and the partial support by the NSF University of Wisconsin Materials Research Science and Engineering Center under (DMR-1720415). I also acknowledge the funding for the preliminary work by the National Science Foundation (NSF) Partnership for Research and Education in Materials (PREM) Awards DMR-0934115 and 1827894. en_US
dc.language.iso en en_US
dc.rights.holder (c) 2020 Karina Riascos Rodriguez en_US
dc.subject Porous coordination polymers en_US
dc.subject Metal-organic frameworks en_US
dc.subject Hysteretic adsorption en_US
dc.subject Carbon dioxide adsorption en_US
dc.subject Nanoporous materials functionalization en_US
dc.subject.lcsh Adsorption en_US
dc.subject.lcsh Coordination polymers en_US
dc.subject.lcsh Copper -- Absorption and adsorption en_US
dc.subject.lcsh Raman effect en_US
dc.subject.lcsh Carbon dioxide en_US
dc.subject.lcsh Porous materials en_US
dc.subject.lcsh Gases -- Absorption and adsorption en_US
dc.subject.lcsh Hysteresis en_US
dc.title Porous coordination pillared layer networks: Hysteretic gas adsorption and functionalization for superior CO2 uptake en_US
dc.type Dissertation en_US
dspace.entity.type Publication Chemical Engineering en_US Ph.D. en_US
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