The increasing concentration of CO₂ in the atmosphere and indoor environments represents an important environmental and technological challenge. Metal–organic frameworks (MOFs), owing to their high porosity, tunable structures, and chemical functionality, represent a promising class of materials for selective CO₂ adsorption. Oxalate–triazolate MOFs based on zinc are particularly interesting, as they have been shown to exhibit high CO₂ selectivity, including under humid conditions. However, the influence of the triazolate ligand structure and metal cation on the properties of these materials has not yet been systematically investigated.

The main hypothesis of this project is that systematic variation of the substitution pattern of the 1,2,4-triazolate ligand and the metal cation can be used to control the structure, porosity, and chemical environment of adsorption sites, thereby enabling optimization of CO₂ adsorption capacity, selectivity, and stability, particularly under humid conditions. The aim of the project is therefore to synthesize and structurally characterize reference and novel oxalate–triazolate MOFs using 1,2,4-triazole and its 3- and 3,5-substituted derivatives, together with Zn, Co, Ni, Cu, Fe, and Mn metal cations. The compounds will be prepared using solution-based, solvothermal/hydrothermal, and mechanochemical methods and characterized by X-ray diffraction, FTIR spectroscopy, thermal and elemental analysis, and electron microscopy. Their porosity and sorption properties will be investigated by N₂ and CO₂ adsorption measurements at different temperatures, including evaluation of the influence of water on CO₂ adsorption and selectivity.

The systematic correlation of chemical structure, porosity, and sorption properties is expected to provide a better understanding of the factors governing selective CO₂ adsorption and to guide the development of novel MOF materials with improved properties for CO₂ capture. The project will also strengthen the existing collaboration between the Ruđer Bošković Institute and the National Institute of Chemistry in Ljubljana and contribute to the training and networking of young researchers.