A novel two-dimensional cationic framework [Zn(TCA)(BIB)]·(NO) (1) (HTCA = tricarboxytriphenyl amine, BIB = 1,3-bis(imidazol-1-ylmethyl)benzene) was successfully achieved. Compound 1 not only presents a moderate affinity toward CO molecules, but it also displays good catalytic performance and substrate selectivity toward both CO conversion with epoxides and Knoevenagel condensation under solvent-free environments, taking advantage of the Lewis acidity endowed by lower four-coordinated Zn(II) centers and Lewis basicity originated from the amines within TCA. More importantly, the bifunctional heterogeneous catalyst compound 1 shows easy recovery and reuse without an obvious decrease of activity. Strikingly, compound 1 exhibits good catalytic efficiency for CO coupled with propylene oxide forming propylene carbonate even at ambient temperature under 1 atm pressure. To the best of our knowledge, compound 1 is presented to be the first cationic MOF holding great promise as a heterogeneous solvent-free catalyst toward both CO epoxidation and Knoevenagel condensation reaction.

Metal-organic frameworks (MOFs) hold great promise as porous matrixes for the incorporation of Au nanoparticles (NPs) because of their rationally designed framework structures. Unfortunately, the as-synthesized bulk MOFs usually vary in the range of micrometer or sub-micrometer size, rendering extremely longer molecular diffusion distance of chemical species. 2D MOF nanosheets with extended lateral dimensions and nanometer thickness are expected to implement fast kinetics and effectively lower mass-transfer barriers during embedding Au NPs process and sequential catalytic reactions. In this study, a novel 2D nanosheet of mixed-ligand Ni(II) MOF (referred to NMOF-Ni) is successfully fabricated. With the merits of well-defined micropores and functional oxygendecorated inner walls, the incorporation of quite monodisperse ultrasmall Au nanoparticles of around 1 nm into NMOF-Ni has been achieved for the first time. The resulting nanocomposites exhibit remarkable catalytic performance and good size selectivity toward aqueous reduction reactions of nitrophenol, taking advantage of ultrasmall Au and 2D nanosheet nature, as well as the intact microporosity of host matrix. The present encouraging findings might shed light on new ways to develop high-performance heterogeneous catalysts by using of 2D MOF nanosheets with functional cavities as hosts for homogeneous distribution of ultrasmall Au NPs. Figure 5. a) Schematic illustration of size selection effect of Au-1@NMOF-Ni for 4-NP and MG 17. b) Catalytic conversion of MG 17 and 4-NP over Au-1@NMOF-Ni. c) Catalytic conversion of MG 17 and 4-NP over pure Au NPs. www.afm-journal.de www.advancedsciencenews.com 1802021 (8 of 8)

The effects of different concentrations of copper (0-800 µmol) on growth, protein contents, peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), and phenylalanine ammonia-lyase (PAL) in Jatropha curcas L. seedlings were assessed by means of pot experiments. Results suggested that increased copper concentrations lead to decreased shoot elongation and seedling biomass. Protein content in the leaves and roots reached their highest levels at the copper concentrations of 400 µmol, while the highest protein content in the stem was observed at 800 µmol copper. POD activity in leaves and stems was unaffected at low copper concentrations, but showed a considerable variation at high copper concentrations. In roots, the highest POD activity was observed at 200 µmol copper. Under copper stress, SOD activity in leaves increased concomitantly with increasing copper up to 400 µmol, and SOD activity in stems and roots showed a slight increase. Catalase activity significantly elevated in leaves and roots but showed no significant changes in stems of the seedlings exposed to copper. A gradual increase of PAL activity in leaves and roots at the copper concentration of 400 and 200 µmol was observed, while PAL activity remained unchanged in stems.

oxidation, [3] the oxygen reduction reaction, [4] hydrogen oxidation reaction, [5] and hydrogen evolution reaction (HER). [6] The scarcity and high cost of Pt have necessitated the development of catalytic systems with increased activity, utilization, and durability of Pt atoms. In this respect, the increase of Pt dispersion on supports by downsizing metals to the atomic scale is of significance for maximizing the Pt utilization and consequently increasing the mass activity and turnover frequency (TOF). [7,8] However, in most cases, the electronic properties of the supported Pt atoms are highly dependent on coordination/supporting environments, which have been shown to be crucial for enabling the Pt catalysts with high intrinsic activity. [9] In recent years, abundant efforts have been made to synthesize the atomic Pt catalysts with tailored coordination environments on diverse supports, such as the N/S-doped carbon materials (Pt 1 /NC, [10] PtRuC [11] ), metal oxides (PtCoO, [12] PtFe 2 O 3 [13] ), metal sulfides (PtMoS 2 [14] ), etc. Anchoring Pt atoms by neighboring strong electronegative atoms will lead to a large charge transfer from Pt to coordinated O/N/S atoms, Platinum-based catalysts occupy a pivotal position in diverse catalytic applications in hydrogen chemistry and electrochemistry, for instance, the hydrogen evolution reactions (HER). While adsorbed Pt atoms on supports often cause severe mismatching on electronic structures and HER behaviors from metallic Pt due to the different energy level distribution of electron orbitals.Here, the design of crystalline lattice-confined atomic Pt in metal carbides using the Pt-centered polyoxometalate frameworks with strong PtO-metal covalent bonds is reported. Remarkably, the lattice-confined atomic Pt in the tungsten carbides (Pt doped @WC x , both Pt and W have atomic radii of 1.3 Å) exhibit near-zero valence states and similar electronic structures as metallic Pt, thus delivering matched energy level distributions of the Pt 5d z 2 and H 1s orbitals and similar acidic hydrogen evolution behaviors. In alkaline conditions, the Pt doped @WC x exhibits 40 times greater mass activity (49.5 A mg Pt −1 at η = 150 mV) than the Pt@C because of the favorable water dissociation and H* transport. These findings offer a universal pathway to construct urgently needed atomic-scale catalysts for broad catalytic reactions.

In this work, TiO-coupled N-doped porous perovskite-type LaFeO nanocomposites as highly efficient, cheap, stable, and visible-light photocatalysts have successfully been prepared via wet chemical processes. It is shown that the amount-optimized nanocomposite exhibits exceptional visible-light photocatalytic activities for 2,4-dichlorophenol (2,4-DCP) degradation by ∼3-time enhancement and for CO conversion to fuels by ∼4-time enhancement, compared to the resulting porous LaFeO with rather high photoactivity due to its large surface area. It is clearly demonstrated, by means of various experimental data, especially for the ·OH amount evaluation, that the obviously enhanced photoactivities are attributed to the increased specific surface area by introducing pores, to the extended visible-light absorption by doping N to create surface states, and to the promoted charge transfer and separation by coupling TiO. Moreover, it is confirmed from radical trapping experiments that the photogenerated holes are the predominant oxidants in the photocatalytic degradation of 2,4-DCP. Furthermore, a possible photocatalytic degradation mechanism for 2,4-DCP is proposed mainly based on the resultant crucial intermediate, 2-chlorosuccinic acid with m/z = 153, that readily transform into CO and HO. This work opens up a new feasible route to synthesize visible-light-responsive high-activity perovskite-type nanophotocatalysts for efficient environmental remediation and energy production.

Metal‐sulfur batteries (MSBs) are considered up‐and‐coming future‐generation energy storage systems because of their prominent theoretical energy density. However, the practical applications of MSBs are still hampered by several critical challenges, i.e., the shuttle effects, sluggish redox kinetics, and low conductivity of sulfur species. Recently, benefiting from the high surface area, regulated networks, molecular/atomic‐level reactive sites, the metal‐organic frameworks (MOFs)‐derived nanostructures have emerged as efficient and durable multifaceted electrodes in MSBs. Herein, a timely review is presented on recent advancements in designing MOF‐derived electrodes, including fabricating strategies, composition management, topography control, and electrochemical performance assessment. Particularly, the inherent charge transfer, intrinsic polysulfide immobilization, and catalytic conversion on designing and engineering of MOF nanostructures for efficient MSBs are systematically discussed. In the end, the essence of how MOFs’ nanostructures influence their electrochemical properties in MSBs and conclude the future tendencies regarding the construction of MOF‐derived electrodes in MSBs is exposed. It is believed that this progress review will provide significant experimental/theoretical guidance in designing and understanding the MOF‐derived nanostructures as multifaceted electrodes, thus offering promising orientations for the future development of fast‐kinetic and robust MSBs in broad energy fields.

No abstract

The convenient synthesis of polymeric yolk-shell microspheres, which possess a hollow shell and an encapsulated spherical core, is both an interest and challenge in polymer chemistry. A method for the synthesis of polymeric yolk-shell microspheres by seed emulsion polymerization is proposed. The present synthesis includes a procedure for swelling the seed latex particles with the hydrophobic monomer mixture, polymerizing the adsorbed and entrapped monomer mixture, forming the coated microspheres, assembling the coated microspheres into sandwichlike ones through phase separation, and removing the seed by solvent etching. Followed this proposal, two kinds of yolk-shell microspheres, one of which contains an ∼200 nm hollow shell of cross-linked poly(styrene-co-acrylamide) and a spherical core of cross-linked polystyrene and the other containing a coordinative segment, are fabricated. The parameters affecting the synthesis of yolk-shell microspheres are investigated, and the phase separation within the seed particles is deemed to play the dominant role.