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A composite cluster with core–shell structure composed of polyoxometalates (POMs) and graphdiyne (GDY) was synthesized and applied for the electrochemical oxygen evolution reaction (OER). Compared with the original POMs and GDY, the composite cluster Co4(PW9)2@GDY demonstrates superior performance and stable electrochemical OER. The core–shell composite cluster exhibited high performance for OER with low potentials and a small Tafel slope. Moreover, high catalytic activity of the cluster was achieved at a high current density. Co4(PW9)2@GDY has excellent catalytic performance and long stability due to its strong electron-transfer ability in the system, higher conductivity, and the structural advantage of pores in GDY. We also tested the OER synergism mechanism between POM and GDY. This would open access and guide us to synthesize novel clusters based on polyoxometalates and graphdiyne. [ABSTRACT FROM AUTHOR]

ABSTRACT: Simultaneously improving the proton conductivity and mechanical properties of a polymer electrolyte membrane is a considerable challenge in commercializing proton exchange membrane fuel cells. In response, we prepared a new series of miscible polymer blends and thus the corresponding crosslinked membranes based on highly sulfonated poly(ether ether ketone) and sulfonated polybenzimidazole. The blended membranes showed more compact structures, due to the acid‐base interactions between the two constituents, and improved mechanical and morphological properties. Further efforts by doping sulfonated graphene oxide (s‐GO) forming composite membranes led to not only significantly elevated proton conductivity and electrochemical performance, but also better mechanical properties. Notably, the composite membrane with the filler content of 15 wt % exhibited a proton conductivity of 0.217 S cm−1 at 80 °C, and its maximum power density tested by the H2/air single PEMFC cell at room temperature reached 171 mW cm−2, almost two and half folds compared with that of the native membrane. As a result, these polymeric membranes provided new options as proton exchange membranes for fuel‐cell applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46547. [ABSTRACT FROM AUTHOR]

Intent on developing efficient proton exchange membranes used for direct methanol fuel cells as well as hydrogen fuel cells, a series of membranes based on sulfonated polyetheretherketone and sulfonated polyphosphazene-graft copolymers is prepared by cross-linking reaction because the former material has good enough mechanical property, while the latter is excellent in the proton transfer. The cross-linked membranes combine the advantages of the two kinds of polymers. Among them, the membrane poly[(4-trifluoromethylphenoxy)(4-methylphenoxy)phosphazene]-g-poly {(styrene)11-r-[4-(4-sulfobutyloxy)styrene]33-sulfonated poly(ether ether ketone)75 (CF3-PS11-PSBOS33-SPEEK75) shows a proton conductivity at 0.143 S cm−1 under fully hydrated conditions at 80 °C and performs tensile strength about five times as much as did the sulfonated polyphosphazene membrane CF3-PS11-PSBOS33. Further doping of sulfonated single-walled carbon nanotubes (S-SWCNTs) into the cross-linked membranes on the screening of additives gives composite membrane CF3-PS11-PSBOS33-SPEEK75-SWCNT possessing proton conductivity of 0.196 S cm−1, even higher than that of Nafion 117 and a tensile strength comparable to that of Nafion 117. However, this significance of the composite membrane in the proton conduction is not observed in the test with a H2/air fuel cell when it shows a maximal power density of 280 mW cm−2 at 80 °C, whereas 294 mW cm−2 is observed for CF3-PS11-PSBOS33-SPEEK75. [ABSTRACT FROM AUTHOR]

In this work, the Keggin-type phosphomolybdic acid (PMo 12) is immobilized in the cavities of Zirconium metal–organic framework (UiO-67) with suitable cage size and limited windows. The PMo 12 @UiO-67 nanocomposite is used as a heterogeneous catalyst for the epoxidation of olefin with excellent retrievability. [Display omitted] • The PMo 12 @UiO-67 nanocomposite is synthesized by the phosphomolybdic acid (PMo 12) as the guest and size-mathched UiO-67 as the host through one-step hydrothermal method. • The PMo 12 @UiO-67 nanocomposite exhibits excellent catalytic activity for the epoxidation of olefin, which could be easily regenerated and recycled for five times without significant loss of catalytic activity. Polyoxometalates (POMs) as the nanocomposites have been applied as the homogeneous catalyst for some organic reactions. Choosing an appropriate support for POMs is an effective approach to solve their low-stability. In this work, the Keggin-type phosphomolybdic acid (PMo 12) is immobilized in the cavities of Zirconium metal–organic framework (UiO-67) with suitable cage size and limited windows. The nanocomposite (PMo 12 @UiO-67) is used as a heterogeneous catalyst for the epoxidation of olefin with excellent retrievability. The above result would help us to develop more polyoxometalate-base heterogeneous catalyst for the epoxidation of olefin. [ABSTRACT FROM AUTHOR]

Quinoxalin-2(1H)-one based design and synthesis produced several series of aldose reductase (ALR2) inhibitor candidates. In particular, phenolic structure was installed in the compounds for the combination of antioxidant activity and strengthening the ability to fight against diabetic complications. Most of the series 6 showed potent and selective effects on ALR2 inhibition with IC50 values in the range of 0.032-0.468 μM, and 2-(3-(2,4-dihydroxyphenyl)-7-fluoro-2-oxoquinoxalin-1(2H)-yl)acetic acid (6e) was the most active. More significantly, most of the series 8 revealed not only good activity in the ALR2 inhibition but also potent antioxidant activity, and 2-(3-(3-methoxy-4-hydroxystyryl)-2-oxoquinoxalin-1(2H)-yl)acetic acid (8d) was even as strong as the well-known antioxidant Trolox at a concentration of 100 μM, verifying the C3 p-hydroxystyryl side chain as the key structure for alleviating oxidative stress. These results therefore suggest an achievement of multifunctional ALR2 inhibitors having both potency for ALR2 inhibition and as antioxidants.