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Efficient photocatalytic CO 2 reduction coupled with the photosynthesis of pure H 2 O 2 is a challenging and significant task. Herein, using classical CO 2 photoreduction site iron porphyrinate as the linker, Ag(I) clusters were spatially separated and evenly distributed within a new metal-organic framework (MOF), namely Ag 27 TPyP-Fe. With water as electron donors, Ag 27 TPyP-Fe exhibited remarkable performances in artificial photosynthetic overall reaction with CO yield of 36.5 μmol g -1  h -1 and ca. 100 % selectivity, as well as H 2 O 2 evolution rate of 35.9 μmol g -1  h -1 . Since H 2 O 2 in the liquid phase can be more readily separated from the gaseous products of CO 2 photoreduction, high-purity H 2 O 2 with a concentration up to 0.1 mM was obtained. Confirmed by theoretical calculations and the established energy level diagram, the reductive iron(II) porphyrinates and oxidative Ag(I) clusters within an integrated framework functioned synergistically to achieve artificial photosynthesis. Furthermore, photoluminescence spectroscopy and photoelectrochemical measurements revealed that the robust connection of Ag(I) clusters and iron porphyrinate ligands facilitated efficient charge separation and rapid electron transfer, thereby enhancing the photocatalytic activity., (© 2024 Wiley-VCH GmbH.)

Molecular sieving is an ideal separation mechanism, but controlling pore size, restricting framework flexibility, and avoiding strong adsorption are all very challenging. Here, we report a flexible adsorbent showing molecular sieving at ambient temperature and high pressure, even under high humidity. While typical guest-induced transformations are observed, a high transition pressure of 16.6 atm is observed for C 2 H 4 at 298 K because of very weak C 2 H 4 adsorption (~16 kJ mol -1 ). Also, C 2 H 6 is completely excluded below the pore-opening pressure of 7.7 atm, giving single-component selectivity of ca. 300. Quantitative high-pressure column breakthrough experiments using 1 : 1 C 2 H 4 /C 2 H 6 mixtures at 10 atm as input confirm molecular sieving with C 2 H 4 adsorption of 0.73 mmol g -1 or 32 cm 3 (STP) cm -3 and negligible C 2 H 6 adsorption of 0.001(2) mmol g -1 , and the adsorbent can be completely regenerated by inert gas purging. Furthermore, it is highly hydrophobic with negligible water adsorption, and the C 2 H 4 /C 2 H 6 separation performance is unaffected at high humidity., (© 2024 Wiley-VCH GmbH.)

Supported metal catalysts with appropriate metal-support interactions (MSIs) hold a great promise for heterogeneous catalysis. However, ensuring tight immobilization of metal clusters/nanoparticles on the support while maximizing the exposure of surface active sites remains a huge challenge. Herein, we report an Ir/WO 3 catalyst with a new enrooted-type MSI in which Ir clusters are, unprecedentedly, atomically enrooted into the WO 3 lattice. The enrooted Ir atoms decrease the electron density of the constructed interface compared to the adhered (root-free) type, thereby achieving appropriate adsorption toward oxygen intermediates, ultimately leading to high activity and stability for oxygen evolution in acidic media. Importantly, this work provides a new enrooted-type supported metal catalyst, which endows suitable MSI and maximizes the exposure of surface active sites in contrast to the conventional adhered, embedded, and encapsulated types., (© 2024 Wiley-VCH GmbH.)

Single-atom catalysts (SACs) are considered prominent materials in the field of catalysis due to their high metal atom utilization and selectivity. However, the wide-ranging applications of SACs remain a significant challenge due to their complex preparation processes. Here, a universal strategy is reported to prepare a series of noble metal single atoms on different non-noble metal oxides through a facile one-step thermal decomposition of molten salts. By using a mixture of non-noble metal nitrate and a small-amount noble metal chloride as the precursor, noble metal single atoms can be easily introduced into the non-noble metal oxide lattice owing to the cation exchange in the in situ formed molten salt, followed by the thermal decomposition of nitrate anions during the heating process. Analyses using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and extended X-ray absorption fine structure spectroscopy confirm the formation of the finely dispersed single atoms. Specially, the as-synthesized Ir single atoms (10.97 wt%) and Pt single atoms (4.60 wt%) on the Co 3 O 4 support demonstrate outstanding electrocatalytic activities for oxygen evolution reaction and hydrogen evolution reaction, respectively., (© 2024 Wiley‐VCH GmbH.)

Considering that CO 2 reduction is mostly a multielectron reaction, it is necessary for the photocatalysts to integrate multiple catalytic sites and cooperate synergistically to achieve efficient photocatalytic CO 2 reduction to various products, such as C 2 hydrocarbons. Herein, through crystal engineering, we designed and constructed a metal-organic framework-derived Zr/Ti bimetallic oxide solid solution support, which was confirmed by X-ray diffraction, electron microscopy and X-ray absorption spectroscopy. After anchoring Au nanoparticles, the composite photocatalyst exhibited excellent performances toward photocatalytic CO 2 reduction to syngas (H 2 and CO production rates of 271.6 and 260.6 μmol g -1  h -1 ) and even C 2 hydrocarbons (C 2 H 4 and C 2 H 6 production rates of 6.80 and 4.05 μmol g -1  h -1 ). According to the control experiments and theoretical calculations, the strong interaction between bimetallic oxide solid solution support and Au nanoparticles was found to be beneficial for binding intermediates and reducing CO 2 reduction, highlighting the synergy effect of the catalytic system with multiple active sites., (© 2024 Wiley-VCH GmbH.)

Porous molecular crystals sustained by hydrogen bonds and/or weaker connections are an intriguing type of adsorbents, but they rarely demonstrate efficient adsorptive separation because of poor structural robustness and tailorability. Herein, we report a porous molecular crystal based on hydrogen-bonded cyclic dinuclear Ag I complex, which exhibits exceptional hydrophobicity with a water contact angle of 134°, and high chemical stability in water at pH 2-13. The seemingly rigid adsorbent shows a pore-opening or nonporous-to-porous type butane adsorption isotherm and complete exclusion of isobutane, indicating potential molecular sieving. Quantitative column breakthrough experiments show slight co-adsorption of isobutane with an experimental butane/isobutane selectivity of 23, and isobutane can be purified more efficiently than for butane. In situ powder/single-crystal X-ray diffraction and computational simulations reveal that a trivial guest-induced structural transformation plays a critical role., (© 2020 Wiley-VCH GmbH.)

Efficient adsorptive separation of propylene/propane (C 3 H 6 /C 3 H 8 ) is highly desired and challenging. Known strategies focus on either the thermodynamic or the kinetic mechanism. Here, we report an interesting reactivity of a metal-organic framework that improves thermodynamic and kinetic adsorption selectivity simultaneously. When the metal-organic framework is heated under oxygen flow, half of the soft methylene bridges of the organic ligands are selectively oxidized to form the more polar and rigid carbonyl bridges. Mixture breakthrough experiments showed drastic increase of C 3 H 6 /C 3 H 8 selectivity from 1.5 to 15. For comparison, the C 3 H 6 /C 3 H 8 selectivities of the best-performing metal-organic frameworks Co-MOF-74 and KAUST-7 were experimentally determined to be 6.5 and 12, respectively. Gas adsorption isotherms/kinetics, single-crystal X-ray diffraction, and computational simulations revealed that the oxidation gives additional guest recognition sites, which improve thermodynamic selectivity, and reduces the framework flexibility, which generate kinetic selectivity., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)