ZIF-8 nanowires enable superior CO2 cycloaddition catalysis through synergistic morphological and Lewis acidity effects

Zeolitic imidazolate frameworks (ZIFs), such as ZIF-8, have emerged as promising heterogeneous catalysts for CO 2 fixation, but their direct application suffers from insufficient Lewis acidity and microporosity-limited mass transport. This work addresses these limitations by synthesizing cetyltrimethylammonium bromide (CTAB)-induced ZIF nanowire precursors followed by rapid low-temperature air calcination (350 °C, 10 min) to produce activated ZIF-8 nanowires (ZIF-8 NWs). This treatment transforms the unstable precursor into a robust ZIF-8 structure, significantly increasing the specific surface area (from 211 to 637 m 2 /g), CO 2 uptake (from 20.7 to 29 cm 3 /g) and Lewis acidity. The resulting ZIF-8 NWs exhibit exceptional catalytic performance in the solvent-free cycloaddition of CO 2 with epoxide (89.5 % yield at 10 h under 80 °C and 0.1 MPa), surpassing that of conventional ZIF-8 nanoparticles (36 %) and ZIF-8 nanosheets (48.9 %), highlighting the key role of morphology and acidity in catalytic CO 2 conversion to cyclic carbonates.