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Abstract: This work reports the fabrication of hierarchical flowerlike platinum nanostructures (Pt nanoflowers, PtNFs) on a 3-aminopropyltriethoxysilane (APTES) monolayer and their electrocatalytic applications. The obtained PtNFs were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and electrochemical methods. The growth mechanism of the PtNFs may be attributed to the inhomogeneous diffusion of PtCl6 2− ions on the surface of the electrode. Moreover, it has been found that the PtNFs modified electrodes exhibit excellent electrocatalytic activity for the oxidation of methanol and the reduction of oxygen when compared to conventional Pt nanoparticle modified electrodes. The increased catalytic activity may be a result of the unique morphology of the PtNFs. [Copyright &y& Elsevier]

Abstract: Y-zeolite/MCM-48 biporous molecular sieve has been synthesized in the mode of overgrowth of MCM-48 on the surface of pre-added zeolite Y. The as-synthesized sample was characterized by XRD, SEM, TEM, IR and nitrogen sorption methods and the corresponding hydrothermal stability was studied. It is found that the composite material exhibits both properties of mesoporous MCM-48 and microporous Y-zeolite sieves. The DFT pore diameter mainly located at 1.2 and 3.2nm. In the progress of synthesis, the pre-added NaY acts as a seed material and MCM-48 overgrow on the surface of Y-zeolite. Compared with MCM-48 molecular sieve, this new biporous molecular sieve shows a higher hydrothermal stability, which results in its thicker pore-wall, and stronger acidity. [Copyright &y& Elsevier]

A grafted 1-(2-hydroxyl-ethyl)-imidazolium-based ionic liquid (GO-HEIMBr) was developed via immobilizing 2-bromoethanol onto an imidazole-modified graphene oxide, which was prepared in a one-pot process. The physicochemical properties of GO-HEIMBr were characterized by atomic force microscopy, X-ray photoelectron spectroscopy, thermogravimetry analysis, Fourier transform infrared spectroscopy, and elemental analysis. In the solvent-free cycloaddition reactions of CO 2 with epoxides to cyclic carbonates, GO-HEIMBr exhibited excellent catalytic activities. A maximum yield of the target cyclic carbonate arrived at 99% using 0.35 mol% catalysts at 140 °C in 4 h. In addition, the catalyst could be easily recovered and reused for seven times without significant loss of activity. A possible catalytic mechanism was proposed for the cycloaddition over GO-HEIMBr. [ABSTRACT FROM AUTHOR]