Diamine-functionalized metal−organic frameworks (MOFs) are known as desirable adsorbents that can capture CO 2 even at low pressures, but the humidity instability of bare MOF powders as well as their shaping have not yet adequately addressed for practical applications. Herein, we report an effective synthetic strategy for fabricating millimeter-sized MOF/poly(vinylidene fluoride) (PVDF) composite beads with different amounts of PVDF binders (30, 40, and 50 wt %) via a phase inversion method, followed by the postfunctionalization of 1-ethylpropane-1,3-diamine (epn). Compared with the pristine MOF powder, the diamine-grafted bead, epn-MOF/PVDF40, upon mixing with 40% binder polymers, exhibited a superior long-term performance without structural collapse for up to 1 month. The existence of the hydrophobic PVDF polymer in the composite material is responsible for such durability. This work provides a promising preparative route toward developing stable and shaped MOFs for the removal of indoor CO 2 .

Control of indoor CO2 concentration to a safe level is important to human health. Metal–organic-framework-based adsorbents show superior adsorption performance at moderate CO2 concentration compared to other solid adsorbents but suffer from low capacities and high regeneration temperature at indoor CO2 concentrations and poor humidity stability. Herein, we report epn-grafted Mg2(dobpdc) (epn = 1-ethylpropane-1,3-diamine) showing a CO2 capacity of 12.2 wt % at an acceptable concentration of 1000 ppm and a practically low desorption temperature of 70 °C, which surpasses the performance of conventional solid adsorbents under the given conditions. After poly­(dimethylsiloxane) coating, this material reveals a significant adsorption amount (∼10 wt %) in humid conditions (up to 98% relative humidity) with structural durability.