Andrés Lancheros Sánchez

Título Tesis: "NOVEL PILLAR-LAYERED METAL ORGANIC FRAMEWORKS BASED ON PYRAZOLE-CARBOXYLATE LINKERS FOR CO2 ADSORPTION"
Profesor (a) Guía: Eduardo Schott
Defensa de Tesis Doctoral: 19 de abril del 2023

Resumen

The rapid increase in greenhouse gases, mainly CO2, in the atmosphere has led to the need for materials that can effectively capture and store CO2. One of the solutions to mitigate this problem is to develop materials that can effectively capture and store CO2. The conventional method relies on using amine solvents to bind to CO2 chemically, but it is still not widely accepted due to its high regeneration cost. Porous solid materials such as Metal-Organic Frameworks (MOFs) have been suggested as CO2 adsorbents due to their-well defined molecular-scale porosity, crystallinity, synthetic tunability, and high CO2 uptake capacity and selectivity.
This Chemistry Ph.D. project synthesized and characterized three novel carboxylate-pyrazole linkers Ap, Bp, and Cp, which were used to create five MOFs using Zn(II)/Cu(II) metal nodes and 4,4’-bipyridine/DABCO pillaring linkers. The carboxylate groups and pyridyl nitrogens are engaged in coordination bond formation with the metal node that propagates in generating 3D porous structures, and the pyrazole nitrogens remain free to interact with CO2. All the materials have shown excellent structural stability and crystallinity. The CO2 uptake was between 3.4-7.20% wt% at 273 K and 75 kPa. For Ap MOFs, changing the metal node from Zn(II) to Cu (II) and replacing the pillaring linker from 4,4’-bipyridine to DABCO makes it possible to increase CO2 adsorption. The isosteric enthalpy of adsorption (Hads) of CO2 adsorption for all of them was between 23-40 kJ/mol, making it more cost-effective for the MOF’s regeneration after CO2 storage. All five MOFs are good candidates for CO2 adsorption because of their stability, capture capabilities, and energy required for CO2 adsorption and regeneration.