In the achievement we introduced a new facile approach to design zeolite Beta@carbon monoliths by controlled carbonization of the zeolite-embedded macroporous polymer matrix. Highly accessible zeolite nanoparticles immobilized within macroporous N-doped carbon walls with hydrophobic nature enables efficient CO2 capture performance with excellent selectivity towards N2 even in a humid post-combustion conditions. Carbonized walls with electric conductivity of 3 S/m reveal large thermo-response at 6-7 V, boosting the heating up to 150 °C with a rate of 50 °C/min. Fast CO2 diffusion to the accessible nanosized zeolites together with efficient electricinduced heating properties of the carbon walls make the developed material appropriate for the electric-swing adsorption regeneration process, that allows at least 100 capture/regeneration cycles per day.
COBISS.SI-ID: 22970134
The high structural and compositional flexibility of metal–organic frameworks (MOFs) shows their great potential for CO2 capture and utilization in accordance with the environmental guidelines of lowcarbon technology developments. HKUST-1 as one of the most intensively studied representatives of MOFs for such purposes excels because of its simplicity of production and high ability to tune its intrinsic properties by various functionalization processes. In the described achievement, ethylenediamine functionalization was performed for the first time in order to thoroughly investigate the amine sorption sites’ impact on the CO2 capture performance of HKUST-1. The placement of ethylenediamine moieties on Cu2+ freemetal sites has been examined in detail and confirmed by using various spectroscopic techniques such as Fourier transform infrared spectroscopy, electron paramagnetic resonance, Raman, and Cu Kedge extended X-ray absorption fine structure/X-ray absorption near edge structure. N2 and CO2 sorption tests have proven that the functionalization reduces both the specific surface area and the CO2 sorption capacity, but on the other hand, it increases the binding energy by 85% (from -20.3 kJ/mol to -36.8 kJ/mol) and CO2/N2 selectivity at 0.15/0.85 bar by 100% and notably improves the kinetics of adsorption in comparison to the pristine HKUST-1 material.
COBISS.SI-ID: 24793091
Metal-organic frameworks (MOFs) represent one of the most intensively emerging group of nanoporous materials with promising applicatove properties in the field of gas capture. However, their applicability in real processes is often limited by their hydrothermal instability. The achievement describes new approach of MOF shaping within the macroporous polymer monoliths, where we successfully improved hydrothermal stability of two representative MOFs namely HKUST-1(Cu) and MOF-5(Zn). Secondary recrystallization of CuO and ZnO initially embedded within the polymer matrices were efficiently solvothermally recrystalllized into corresponding MOFs with addition of proper organic ligands. Formed MOF phases located within the polymers exhibit high accessibility for hosting gas molecules, whereas hydrophobic nature of polymer matrices act as a water-repelling component, enabling to newly developed composites high CO2 capture perfromances even in the presence of humidity.
COBISS.SI-ID: 6072090
Metal–organic frameworks (MOFs) are getting closer to finally being used in commercial applications. In order to maximize their packing density, mechanical strength, stability in reactive environments, and many other properties, the compaction of MOF powders is a fundamental step for the application field of research of these extraordinary materials. In particular, HKUST-1 is among the most promising and studied MOF. Here we prove that the tableting of HKUST-1 powders without any damage of the lattice is possible and easy to get. For the first time, this kind of investigation has been performed exploiting its peculiar magnetic properties with the aid of electron paramagnetic resonance spectroscopy. Indeed, they have allowed us to explore in detail all the smallest changes induced in the paramagnetic paddle-wheel units by the application of the mechanical pressure on the material. This original approach has permitted us to unveil the main source of structural instability of HKUST-1 during compaction, that is, the water molecules adsorbed by the powdered sample before tableting and finally to establish a proper compaction protocol. Our conclusions are also fully supported by the results obtained with powder X-ray diffraction, Fouriertransform infrared spectroscopy, thermogravimetric analysis, water sorption isotherms, and surface area estimation with the Brunauer– Emmett–Teller method, which prove that the tablet of HKUST-1 obtained by this new protocol actually preserves the crystal structure and porosity of the pristine powders. A morphological characterization has also been conducted with a combined use of optical and atomic force microscopies.
COBISS.SI-ID: 6557466