Ground-level ozone (O 3 ) poses a threat to both human health and ecosystems; the development of O 3 decomposition catalysts is thus of fundamental and practical significance. In the past decades, metal oxides have been widely investigated for O 3 elimination due to their low cost and high catalytic activity. Recently, it has been demonstrated that metal−organic frameworks (MOFs) could also show high performance in the removal of O 3 and even other airborne gaseous pollutants at the same time. Herein, we report a facile synthetic method to prepare the composite of the well-known MOF, UiO-66-NH 2 , and birnessitetype manganese dioxide, namely, δ-MnO 2 , where the nanosheets of δ-MnO 2 are vertically aligned and densely grown on the crystal surfaces of UiO-66-NH 2 . The δ-MnO 2 /UiO-66-NH 2 composite could completely remove low-concentration O 3 (5 ppm) in both dry and highly humid (RH = 80%) air at ambient temperature and pressure with a space velocity of 2000 L h −1 g −1 . In contrast, a single-phase sample of δ-MnO 2 or the typical O 3 decomposition catalyst, α-MnO 2 , showed a much lower O 3 removal efficiency under the same experimental conditions. Due to the ultrathin morphology (high surface area) and well-separated distribution (no aggregation) of δ-MnO 2 nanosheets in the δ-MnO 2 /UiO-66-NH 2 composite, there are rich Mn 2+ /Mn 3+ atoms and oxygen vacancies on its surface, contributing to its high performance in catalytic O 3 decomposition. This work demonstrated a facile method to prepare MOF-based composites with fascinating nanostructures and high catalytic activity in O 3 decomposition, which are also potentially useful in other catalytic reactions.

Propyne/propylene separation is important in the petrochemical industry but challenging due to their similar physical properties and close molecular sizes. Metal–organic frameworks (MOFs) are a class of promising adsorbents for light hydrocarbon separations. Among them, the so-called “flexible-robust” MOFs combine the advantages of flexibility and rigidity in structure and could show enhanced gas separation selectivity as well as improved gas uptake at low pressure. Interpenetrated MOFs offer a platform to explore the “flexible-robust” feature of MOFs based on their subnetwork displacement in the process of gas adsorption. Herein, we present two hydrolytically stable MOFs (BUT-308 and BUT-309) with interpenetrated structures and fascinating propyne/propylene separation performance. BUT-308 is composed of interpenetrated 2D Cu(BDC-NH2)BPB layers (H2BDC-NH2 = 2-aminobenzene-1,4-dicarboxylic acid; BPB = 1,4-bis(4-pyridyl)benzene), while BUT-309 consists of twofold interpenetrated 3D pillared-layer Cu2(BDC-NH2)2(BPB-CF3) nets (BPB-CF3 = 2-trifluoromethyl-1,4-bis(4-pyridyl)benzene). Gas adsorption measurements showed that BUT-309 was a “flexible-robust” adsorbent with multistep adsorption isotherms for C3H4 rather than C3H6 at a wide temperature range. The guest-dependent pore-opening behavior endows BUT-309 with high potential in the C3H4/C3H6 separation. The C3H4 adsorption measurements of BUT-309 at 273–323 K showed that the lowering of the temperature induced the pore-opening action at lower pressure. Column breakthrough experiments further confirmed the capability of BUT-309 for the efficient removal of C3H4 from a C3H4/C3H6 binary gas, and the C3H6 processing capacity at 273 K (15.7 cm3 g–1) was higher than that at 298 K (35.2 cm3 g–1). This work shows a rare example of “flexible-robust” MOFs and demonstrated its high potential for C3H4/C3H6 separation.