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Ni-doped spherical mesoporous carbon catalysts (Ni/C n ) were prepared via one-pot hydrothermal carbonization of microcrystalline cellulose (MCC) with nickel acetate as the Ni source. This exhibited a high conversion rate for p-nitrophenol (PNP) hydrogenation to p-aminophenol (PAP). The obtained catalysts contained 0.87–6.84 wt% nickel content that primarily consisted of metallic nickel, with a small amount of nickel oxide. The Ni additive could be beneficial in the formation of the mesoporous structure. The results showed that as the Ni content increased, the mesoporous percentage increased. The doped Ni was monodispersed particles added into the carbon skeleton with an average particle size of 23.6 nm. They were surrounded by ordered striped carbon that exhibited a graphite-like structure. The catalytic hydrogenation reaction took place at normal temperatures and pressure exhibited high catalytic activity. The degradation rate of PNP reached 99.7% when 0.30 g of the Ni/C0.2-900 catalysts was used for a reaction time of 40 min, with corresponding apparent rates constant of 1.68 × 10−3 S−1, apparent activation energy of only 43.25 kJ/mol. [ABSTRACT FROM AUTHOR]

Abstract  The pure silica mesoporous molecular sieve MCM-41 was synthesized under hydrothermal conditions. Pd/Si-MCM-41 was prepared by the incipient wetness impregnation of pure silica MCM-41 with PdCl2 as precursor. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms at 77 K, inductively coupled plasma (ICP) spectroscopy measurements. The formation of Pd particles reduced the crystalline character of Si-MCM-41, but the structure of Si-MCM-41 framework was retained. The designed Pd/Si-MCM-41 mesoporous material was used as catalysts for hydrogenation of rosin, and showed excellent catalytic performance. Such outstanding catalytic performance should be attributed to the proper size of Pd particles and its high dispersion. [ABSTRACT FROM AUTHOR]

The mesoporous molecular sieve Zr-MCM-41 was synthesized under hydrothermal conditions. Zr-MCM-41 material was impregnated using sulfuric acid to prepare SO/Zr-MCM-41. The obtained materials were characterized by XRD, FT-1R,N2 adsorption/desorption and NH3-TPD analysis technique. The results indicated that SO/Zr-MCM-41 was of better mesoporous structure, long range ordering and crystallites, and that SOexisted in the skeleton of Zr-MCM-41 and enhanced its acidity. SO/Zr-MCM-41 were firstly used as catalyst in the esterification of terpineol. The catalytic results were compared with those obtained by using sulfuric acid (33%), HY, HZSM-5 and SO/ZrO2 as catalysts. It was showed that SO/Zr-MCM-41 were not only of better catalytic activity and selectivity, but also of better regenerable performance. The effects of synthesis methods of catalysts and Si/Zr mole ratio on catalytic properties were also studied. In addition, AlCl3 was supported on the synthesized mesoporous molecular sieves to get composite catalysts that were firstly used to catalyze the polymerization of a-pinene. It was showed that the catalytic result of thecomposite catalystwas better than that AlCl3 alone. [ABSTRACT FROM AUTHOR]

Abstract Porous palladium nanostructures were prepared on a copper sheet previously fixed over the plasma high-temperature area by H2+He arc plasma method. However, dispersed palladium nanoparticles with diameters in 5090nm were obtained on the inner wall of vacuum chamber. SEM, TEM, EDXA, XRD and BET were employed to characterize the palladium porous materials. SEM images show that porous palladium nanostructures are composed of spherical particles with diameters of 353nm. This special structure with large surface to volume ratio can be recycled easily for application in the field of catalysis. [ABSTRACT FROM AUTHOR]