20.500.12556/RUL-189707 Ligand-mediated defects unlock fast and regenerable CO₂ capture in NICS-24 metal–organic framework Indoor CO$_2$ capture is an emerging strategy to improve air quality while reducing the energy cost of ventilation. Practical adsorbents must exhibit high affinity at low partial pressures, fast sorption kinetics, and energy-efficient regeneration. Here, we show that the Zn−oxalate guanazolate framework NICS-24, a promising platform for CO$_2$ capture at 400−1000 ppm, can be transformed into a high-performance indoor sorbent via ligand-mediated defect engineering (LMDE). Postsynthetic treatment with CF$_3$- and SCH$_3$-functionalized azolate linkers (denoted as FMeTz and SMeTz) induces an equilibrium-limited partial Zn-leaching process that generates vacancy-type defects while preserving the long-range crystallinity and Zn−linker connectivity. Comprehensive characterization (PXRD, EDS, ICP, XPS, PALS, FTIR, and multinuclear SSNMR) reveals subtle unit-cell contraction, increased local disorder, and modest expansion of accessible ultramicropore free volume. These defect-related changes markedly enhance CO$_2$ adsorption and transport. At 25 °C and 1000 ppm, the NICS-24-modified materials show more than a 2-fold increase in uptake (0.36 to 0.77 mmol/g), along with rapid kinetics and improved thermal-swing regeneration. The SMeTz-treated material retains high working capacity after regeneration at 70 °C and exhibits stable cycling. In situ DRIFTS and ex situ SSNMR confirm reversible physisorption dominated by interaction with defect-associated O−H/N−H environments, directly linking vacancy-type defect domains to enhanced low-pressure uptake, accelerated transport kinetics, and regenerability. Although water adsorption remains competitive, the frameworks are hydrolytically robust, highlighting LMDE-modified NICS-24 as a promising platform for indoor CO$_2$ capture under dry conditions. oxides metal organic frameworks defects adsorption inorganic carbon compounds kemijska tehnologija ogljikov dioksid notranje okolje kakovost zraka adsorbenti true false true Angleški jezik Slovenski jezik Članek v reviji 2026-10-13 11:03:15 2026-10-13 11:03:17 2026-10-14 04:14:04 0000-00-00 00:00:00 2026 0 0 Str. 26005–26016 iss. 25 Vol. 148 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 66 1520-5126 10.1021/jacs.6c04820 283315971 jacs.6c04820.pdf jacs.6c04820.pdf 1 AAC130FDE7C8E7C0E0C8DA8CCA418DC4 cdfff58874e75c0f527d3d571f09c30a08d1e8503834d00669f0f15342c8d6cb 529cae04-c6e5-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=250450 https://pubs.acs.org/jacsat/article/148/25/26005/5171519/Ligand-Mediated-Defects-Unlock-Fast-and 0 00b6b47b-c6e5-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=250449 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0