The precise identification of single‐atom catalysts (SACs) activity and boosting their efficiency toward CO2 conversion is imperative yet quite challenging. Herein, for the first time a series of porous organic polymers is designed and prepared simultaneously, containing well‐defined M–N4 and M–N2O2 single‐atom sites. Such a strategy not only offers multiactive sites to promote the catalytic efficiency but also provides a more direct chance to identify the metal center activity. The CO2 photoreduction results indicate that the introduction of salphen unit with Ni–N2O2 catalytic centers into pristine phthalocyanine‐based Ni–N4 framework achieves remarkable CO generation ability (7.77 mmol g–1) with a high selectivity of 96% over H2. In combination with control experiments, as well as theoretical studies, the Ni–N2O2 moiety is evidenced as a more active site for CO2RR compared with the traditional Ni–N4 moiety, which can be ascribed to the M–N2O2 active sites effectively reducing the energy barrier, facilitating the adsorption of reaction radicals *COOH, and improving the charge transportation. This work might shed some light on designing more efficient SACs toward CO2 reduction through modification of their coordination environments.

Five members of a new family of polyoxometalate (POM)-ligated trinuclear lanthanoid (Ln) clusters with the general formula K20Li2[Ln3(μ3-OH)(H2O)8(AsW9O33)(AsW10O35(mal))]2·17H2O [Ln = Dy (1Dy), Tb (2Tb), Gd (3Gd), Eu (4Eu), and Sm (5Sm), mal = malate] have been synthesized, all of which consist of the dimeric {[Ln3(μ3-OH)(H2O)8(AsW9O33)[AsW10O35(mal)]}(11-) polyanion constructed from a {AsW9O33} and a {AsW10O35(mal)} building block linked by a tri-Ln cluster [Ln3(μ3-OH)(H2O)8](8+), where the two malate ligands play a key bridging role. The {AsW10O35(mal)} subunit can be viewed as the {AsW9O33} building block anchoring an additional tungsten center [WO2(mal)]. The electrospray ionization mass (ESI-MS) spectra indicate that the dimeric fragments of 1Dy and 2Tb are unstable, which are apt to produce the subunit [KH5Ln3(OH)(H2O)(AsW9O33)2](4-) in solution. The solid-state photoluminescence measurements display the yellowish green emission for 1Dy and 5Sm, green emission for 2Tb and reddish orange emission for 4Eu, which are attributed to the Ln(III) f-f electron transitions. Magnetic property studies indicate that 1Dy displays probable SMM behaviour with slow magnetization relaxation, whereas the weak antiferromagnetic interactions exist in two {Ln3} clusters for 2Tb-5Sm.

Ground-level ozone (O3) is one of the main airborne pollutants detrimental to human health and ecosystems. However, the designed synthesis of high-performance O3 elimination catalysts suitable for broadly variable air compositions, especially a variable water vapor content, remains daunting. Herein, we report a new manganese-based metal organic framework, [Mn3(μ3-OH)2(TTPE)­(H2O)4]·2H2O (H4TTPE = 1,1,2,2-tetrakis­(4-(2H-tetrazol-5-yl)­phenyl) ethane), denoted as ZZU-281. ZZU-281 catalyzes O3 decomposition with a nearly constant 100% working efficiency over the entire humidity range from dry (≤5% relative humidity (RH)) to high humidity (90% RH). We found that the maintainable coordinated water molecules and OH groups are activated by Mn2+, becoming active sites for O3 transfer to O2 with a low activation energy. The unique open channels, water retainability, and water stability of ZZU-281 further support the high catalytic performance. This work opens a new avenue for designing efficient catalysts for O3 elimination in practice.

No abstract

The nona-Cu(II)-containing tungstoarsenate(III) [H4{Cu(II)9As(III)6O15(H2O)6}(α-As(III)W9O33)2](8-) (1a) has been synthesized and characterized. Polyanion 1a comprises a unique, cylindrical {Cu(II)9As(III)6O15(H2O)6}(6+) cluster, which forms a large central cavity and is capped on either end by an [α-As(III)W9O33](9-) capping group. It exhibits remarkable activity against K562 leukaemia cells, as well as induces HepG2 cell apoptosis and autophagy.