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The organization of different nano objects with tunable sizes, morphologies, and functions into integrated nanostructures is critical to the development of novel nanosystems that display high performances in sensing, catalysis, and so on. Herein, using acetylacetone as a chelating agent, phenolic resol as a carbon source, metal nitrates as metal sources, and amphiphilic copolymers as a template, we demonstrate a chelate-assisted multicomponent coassembly method to synthesize ordered mesoporous carbon with uniform metal-containing nanoparticles. The obtained nanocomposites have a 2-D hexagonally arranged pore structure, uniform pore size (~4.0 nm), high surface area (~500 m(2)/g), moderate pore volume (~0.30 cm(3)/g), uniform and highly dispersed Fe(2)O(3) nanoparticles, and constant Fe(2)O(3) contents around 10 wt %. By adjusting acetylacetone amount, the size of Fe(2)O(3) nanoparticles is readily tunable from 8.3 to 22.1 nm. More importantly, it is found that the metal-containing nanoparticles are partially embedded in the carbon framework with the remaining part exposed in the mesopore channels. This unique semiexposure structure not only provides an excellent confinement effect and exposed surface for catalysis but also helps to tightly trap the nanoparticles and prevent aggregating during catalysis. Fischer-Tropsch synthesis results show that as the size of iron nanoparticles decreases, the mesoporous Fe-carbon nanocomposites exhibit significantly improved catalytic performances with C(5+) selectivity up to 68%, much better than any reported promoter-free Fe-based catalysts due to the unique semiexposure morphology of metal-containing nanoparticles confined in the mesoporous carbon matrix.

Partial hydrogenation of benzene to cyclohexene is attractive in terms of feedstock accessibility, atomic economy, and operational simplicity. Herein, a series of Ru/ZrO2 catalysts were prepared by post-treatment of a binary Ru-Zn/ZrO2 catalyst using 5-30 wt % NaOH aqueous solutions. Alloying between Ru and Zn was evidenced for the catalyst post-treated only by water (Ru/ZrO2-0). Alkaline post-treatment removed metallic Zn, forming smaller Ru nanoparticles. Concomitantly, the hydrophilicity of the catalysts was increased and maximized on the 10 wt % NaOH-treated catalyst (Ru/ZrO2-10). In partial hydrogenation of benzene, the Ru/ZrO2-0 catalyst displayed the highest turnover frequency but the lowest initial selectivity to cyclohexene, whereas the Ru/ZrO2-10 catalyst exhibited the highest initial selectivity (86 %) and yield of cyclohexene (51 %) among the catalysts investigated. A quantitative relationship between the initial selectivity to cyclohexene and the hydrophilicity of these catalysts was identified, which rationalizes the significant impact of alkaline post-treatment on selectivity enhancement in partial hydrogenation of benzene to cyclohexene over Ru/ZrO2 catalysts. [ABSTRACT FROM AUTHOR]

Small and stable: Fe2O3 nanoparticles are homogeneously anchored onto reduced graphene oxide through the simultaneous hydrolysis of Fe(acac)3 and reduction of graphene oxide. This nanohybrid is highly resistant to sintering and retains its small particle size upon reduction at 723 K and long‐term Fischer–Tropsch synthesis at 543 K (see figure). This work validates the prospect of graphene‐related nanomaterials in challenging high‐temperature applications. [ABSTRACT FROM AUTHOR]

Robust iron‐on‐graphene catalyst The cover picture shows highly dispersed iron oxide nanoparticles anchored on reduced graphene oxide (rGO) with defects. In their Communication on p. 714 ff., B. Sun et al. demonstrate the one‐pot fabrication of such materials using different metal acetylacetonates and GO as starting materials. The outstanding stability of the small iron oxide nanoparticles on rGO is validated in high‐temperature reduction and in long‐term gas‐phase Fischer‐Tropsch synthesis. This work presents the promising future of the graphene‐related nanomaterials, even in very challenging high‐temperature applications by facile materials design. [ABSTRACT FROM AUTHOR]

Site-specific deposition of metal nanoparticles (NPs) on metal oxide surfaces is challenging but of particular importance for the development of catalytic materials with improved or new performance. We report here that Ru NPs can be directed to the rutile/anatase junction of P25 TiO 2 via a facile wetness impregnation–chemical reduction method at room temperature. In the partial hydrogenation of benzene to cyclohexene, the Ru/P25 catalyst outperformed the Ru NPs supported on phase-pure rutile and anatase as well as physically mixed Ru/rutile and Ru/anatase, both in activity and in selectivity. We identified a unique electron-deficient Ru species (Ru δ+ ) on the Ru/P25 catalyst originated from the Ru O linkages connecting the Ru NPs with the rutile/anatase junction. This interfacial Ru δ+ species gave rise to an especially tightly bonding benzene species while lowering the adsorption strength of cyclohexene, thus granting the Ru/P25 catalyst superior activity and unprecedented selectivity toward cyclohexene (initial selectivity 90%). [ABSTRACT FROM AUTHOR]

Abstract: A high-performance Pd/Fe3O4 catalyst for aqueous-phase reforming (APR) of ethylene glycol (EG) to H2 was prepared facilely by the co-precipitation method. After proper activation, the Pd was present as highly dispersed metallic nanoparticles with dimension of <3nm, and the Fe was present as magnetite. When compared to Pd catalyst supported on Fe2O3, NiO, Cr2O3, Al2O3, or ZrO2 prepared by incipient wetness impregnation, the Pd/Fe3O4 catalyst displayed superior catalytic performance in terms of activity, selectivity, and stability. The intrinsic activity of the Pd/Fe3O4 catalyst was about three times of that of the second most active Pd/Fe2O3 catalyst under the same reaction conditions. In addition, the Pd/Fe3O4 catalyst retained ∼80% of its initial activity after reaching the steady-state. Notably, the Pd/Fe3O4 catalyst possessed the highest turnover frequency of H2 (109min−1) reported so far, showing its promise as a new practical catalyst for APR of biomass-derived oxygenates to H2. The excellent catalytic performance of the Pd/Fe3O4 catalyst was attributed to the enhanced synergistic effect between small Pd nanoparticles and magnetite in promoting the water–gas shift reaction, the rate-determining step in APR of EG over Pd-based catalysts. [Copyright &y& Elsevier]

Uniform Co–B nanoparticles were synthesized for the first time by chemical reduction of cobalt ion with borohydride in an oil-in-water microemulsion system comprising cyclohexane, polyethylene glycol, and water. The particle size was controlled by modulating the cyclohexane content. With the characterization of X-ray diffraction, selective area electronic diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy, the resulting Co–B nanoparticles were identified to be amorphous alloys ranging in size from 6 to 20 nm. During liquid-phase cinnamaldehyde hydrogenation, the as-synthesized Co–B catalyst was extremely active and more selective than the regular Co–B prepared in aqueous solution. Furthermore, this catalyst also was found to be more durable during the hydrogenation process. [Copyright &y& Elsevier]

Abstract: Uniform spherical Co-B amorphous alloy nanoparticles were prepared by ultrasound-assisted reduction of Co(NH3)2+ 6 with BH− 4 in aqueous solution, and the particle size was adjusted by changing either the ultrasound power or the ultrasonication time. During liquid-phase cinnamaldehyde (CMA) hydrogenation, the as-prepared Co-B catalyst exhibited much higher activity and better selectivity to cinnamyl alcohol (CMO) than the regular Co-B obtained by direct reduction of Co2+ with BH− 4. The higher activity can be attributed to both the higher dispersion of Co active sites () and the higher intrinsic activity (). The higher selectivity can be attributed to both the uniform Co-B amorphous alloy particles and the strong electronic interaction between Co and B, which enhances the competitive adsorption of Cgainst Cn the CMA molecule. Meanwhile, the stronger adsorption for hydrogen on Co active sites was more favorable for Cnation in comparison with the Cnation. [Copyright &y& Elsevier]

Abstract: Mesoscopically spherical Ni–B amorphous alloy nanoparticles were prepared through self-assembly of an ionic surfactant hexadecyltrimethylammonium bromide. During liquid-phase nitrobenzene hydrogenation, the as-prepared mesoporous Ni–B catalyst exhibited higher activity and selectivity than the regular Ni–B obtained via direct chemical reduction, apparently owing to the higher surface area, which ensured high dispersion of active sites and the mesoporous channels that might facilitate diffusion and adsorption of reactant molecules. [Copyright &y& Elsevier]