A novel Au/Fe–V–Ox/Al2O3 catalyst displayed remarkable activity and good stability for CO oxidation in the simulated atmosphere of a CO2 laser with high CO2 levels up to 60 vol% and stoichiometric or even lower O2/CO ratio. The improved surface labile lattice oxygen on the FeOx and VOx modified Al2O3 plays a crucial role in its outstanding performance for the CO oxidation reaction in an oxygen-poor atmosphere.

Correction for ‘A series of nano/micro-sized metal–organic frameworks with tunable photoluminescence properties’ by Yuhua Zheng et al., CrystEngComm, 2015, 17, 2321–2326.

Present studies on metal–organic frameworks (MOF) mainly focus on macro-scaled single crystals. However, the realization of MOF nanocrystals via a bottom-up one-step method still remains a significant challenge. Here, hierarchically assembled nanostructures of lanthanide-based MOFs with 1D and 3D morphologies have been successfully fabricated via a simple and rapid solution phase method at room temperature. Upon UV excitation, these nanomaterials exhibit highly efficient tunable luminescence properties, which come from the Eu3+ or Tb3+ ions. Moreover, white-light emission can be achieved by co-activating the organic ligand, Eu3+ and Tb3+ ions in the nano-MOFs.

An orange-like catalyst of Pd nanoparticles supported by magnetic Fe3O4/polypyrrole nanocomposite is facilely prepared. It shows great activity for Suzuki coupling reactions in neat water under atmospheric pressure. This magnetic and water-soluble catalyst avoids the use of toxic solvents in traditional process of coupling reactions and can be easily recovered by mean of a convenient magnetic separation technique, demonstrating in both environmental friendliness and recyclability.

In this paper, the coatings with friction-reducing properties were investigated using both sol–gel and self-assembling techniques. The thin film of TiO2 was firstly prepared on glass substrates via a sol–gel method, followed by calcinating at 480 °C. The films of fatty acid were then deposited on the TiO2 surface to obtain a dual-layer film. The contact angle measurement and FT IR spectroscopy were used to determine the wetting behavior and chemical structure of films, respectively. The friction-reducing behavior of films sliding against a steel ball was examined on a macro friction and wear tester. It is found that fatty acid is strongly adsorbed on sol–gel derived TiO2 surface. Good friction-reducing behavior is observed for the glass substrate after duplex surface-modification with TiO2 surface obtained by sol–gel method and top layer of fatty acid.

In this study, a simple two-step process was developed to render zinc (Zn) surfaces super-hydrophobic for the purpose of lowering friction and increasing wear resistance. Zn substrates were immersed in an aqueous solution of N,N-dimethylformamide (4%, volume fraction v/v) to fabricate a ZnO film consisting of uniform and well-packed nanorods. A self-assembled monolayer of stearic acid was then prepared on the ZnO-nanorod film to acquire super-hydrophobicity. Scanning electron microscopy, Fourier transform infrared microscopy, and water contact-angle measurements were employed to analyze the morphological features, the chemical composition, and super-hydrophobicity of freshly prepared samples. Moreover, the friction and wear behavior of the organic–inorganic composite film sliding against steel was evaluated in a ball-on-plate configuration using a UMT-3 friction and wear tester. It was found that the stearic acid overcoat on the nanostructured ZnO film led to a large water contact angle of ~155° as well as to significantly decreased friction and greatly extended wear resistance.

A zinc substrate was firstly immersed in an aqueous solution of N, N-dimethylformamide (DMF) solution and then chemically modified with oleic acid to generate a superhydrophobic surface. The morphological features, chemical composition and superhydrophobicity of the resultant superhydrophobic surface were analyzed by means of scanning electron microscopy, Fourier transform infrared microscopy and water contact angle (WCA) measurements, respectively, and the tribological behavior of films was evaluated by sliding the superhydrophobic films against a steel ball under 0.5 N normal load using a reciprocating ball-on-plate tribo-tester. It was found that the as-obtained superhydrophobic surface on the roughened (oxidized) zinc substrate had a WCA as high as 155°, and effectively reduced friction and largely increased antiwear life, due to the combined beneficial effects of nanotexturing of DMF treatment and nanolubrication of self-assembled oleic acid overcoat.

This article reviews our recent results on the steam reforming of methanol over a series of NiAl-layered double hydroxide catalysts prepared by the co-precipitation method. The influence of calcination temperature, reaction temperature, pretreatment temperature and atmospheres, inorganic salt ions and steam to methanol ratio on the catalytic performance was studied. The major products for many of the catalysts were H2, CO, CO2 and CH4. However, the product composition varies significantly with the experimental parameters and high selectivity for CO2 and H2 was observed under various conditions, showing the potential of Ni based catalysts for the production of highly pure hydrogen.

Direct gaseous-phase epoxidation of propylene over nanogold catalysts in co-presence of H2 and O2 has been extensively studied. Many researchers have made important progress in this field, and a survey of the literature published to date is presented in this article. The salient features are the nature of the nanogold particles and the Ti-based support materials.

Production of hydrogen by methanol steam reforming has been studied over a series of Ni/Al layered double hydroxide catalysts prepared by the co-precipitation method, with the aim to develop a stable catalyst that can be used in a membrane-joint performer at temperatures greater than 300 °C. H2, CO and CO2 are generally the major products together with trace amounts of CH4. The presence of potassium and/or sodium cations was found to improve the activity of methanol conversion. The selectivity for CO2 rather than CO was better with K ions than Na ions, especially at higher temperatures (e.g. 390–400 °C). Methanol steam reforming over a K-promoted Ni/Al layered double hydroxide catalyst resulted in better activity and similar stability compared to a commercial Cu catalyst.

This paper presents the results of the steam reforming of methanol on an as-prepared NiAl-layered double hydroxide catalyst pretreated in two different atmospheres and then the reaction at a high temperature of 390∘C with feed having various steam-to-methanol ratios. The product composition was found to vary significantly with the pretreatment atmosphere. High activity and stability with high selectivity for CO2 and H2 and low level CO and no methane formation in a broad range of the H2O/CH3OH ratio was observed when the catalyst was preheated in the diluted H2 stream. Whereas in the case of pretreatment in the reactive stream of the mixture of steam and methanol, the formation of methane and its increase with more steam in feed was obtained and with time on line the catalyst deactivated with an increase in CO formation and decreases in CO2, H2 and CH4 production. A catalyst with optimal ratio of ionic Ni in different chemical environment is suggested to obtain an active, selective and stable reforming catalyst.

•A magnetically recoverable palladium-based catalyst was prepared.•The Fe3O4@SiO2–2N–Pd(II) catalyst is highly economical and easy-to-prepare.•The catalyst showed high activity for aerobic oxidation of alcohols and carbonylative Suzuki coupling reaction.•The “green” catalyst was easily recovered via external magnetic field.•The catalytic efficiency remains unaltered even after 6 repeated cycles.A novel Pd(II) complex immobilized on ethylenediamine-functionalized core–shell magnetic nanoparticles [Fe3O4@SiO2–2N–Pd(II)] was successfully synthesized by a facile procedure, and various characterizations (TEM, XRD, FT-IR, TGA, XPS and VSM) were performed to identify its intrinsic features. The amino groups in two kinds from ethylenediamine-functionalized magnetic nanoparticles (Fe3O4@SiO2–2N) performed as robust anchors and efficient stabilizers during the fabrication of Fe3O4@SiO2–2N–Pd(II). As a heterogeneous phosphine-free Pd(II) complex catalyst, it showed excellent catalytic activity for aerobic oxidation of alcohols, and up to >99% yield of unsymmetrical biaryl ketone was obtained in the carbonylative Suzuki coupling reaction of carbon monoxide, 4-methylbenzeneboronic acid and the 4-iodonitrobenzene. Moreover, the catalyst could be completely recovered by magnetic separation from the reaction mixture and remained unaltered activity even after six repeated cycles.Download full-size image

In a H2 and O2 mixture, the reaction of propene switches between hydrogenation and epoxidation over Au/Ti-based oxides. Reaction pathways are strongly dependent on the size of Au particles and on the presence of alkalis. The hydrogenation prevails over Au clusters smaller than 2.0 nm (in the absence of alkalis) and over Au nanoparticles larger than 5.0 nm. Alkali contamination can switch hydrogenation to epoxidation over Au clusters and promote epoxidation over Au nanoparticles with diameters of 2.0–5.0 nm. It was also confirmed that the hydrogenation of propene is enhanced by the addition of a small amount of O2. Switching of product by alkalis and enhancement of hydrogenation by oxygen are interpreted by parallel and competitive reaction pathways.Graphical abstractThe size of Au particles and the presence of alkalis can switch hydrogenation and epoxidation of propene over Au/Ti-based oxides in a mixture with H2 and O2.Download high-res image (40KB)Download full-size imageHighlights► Gold was deposited on three types of support with or without Ti. ► Propane was formed over Au particles (>5.0 nm) and Au clusters (<2.0 nm). ► Alkali contaminants can turn hydrogenation to epoxidation on Au clusters. ► Propane formation was enhanced by O2. ► Switching between hydrogenation and epoxidation of propene was discussed.