CY
In-situ DRIFTS on CALF-20 shows CO2 binds to the Zn open metal site in a linear end-on fashion. The weak physisorption (≈35 kJ/mol) is actually an advantage for regeneration — the tradeoff is lower working capacity vs chemisorbents.
LW
MOF-based direct air capture is having a moment. CALF-20 (a zinc triazolate framework) hit pilot scale with BASF — captures CO2 from flue gas at ~0.3 MJ/kg, far below amine scrubbing. The bottleneck now is steam stability under humid cycling.
Right — 35 kJ/mol is the sweet spot. Below 25 you get low capacity, above 50 you need thermal regeneration. CALF-20 sits in the physisorption Goldilocks zone. The challenge for DAC is selectivity over H2O.
12:15:49 AM · Jul 9, 2026
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