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Abstract: Mesoporous silica KIT-6-, SBA-15-, and MCM-41-supported Ni catalysts (Ni/KIT-6, Ni/SBA-15, and Ni/MCM-41) were prepared via impregnation method and studied for CO2 reforming of CH4. The catalysts were characterized by X-ray diffraction analysis, N2 physisorption measurements, scanning electron microscopy, transmission electron microscopy, and temperature-programmed oxidation (O2-TPO). The Ni/KIT-6 catalyst exhibited higher catalytic activity and long-term stability compared with Ni/SBA-15 or Ni/MCM-41. The conversion of CH4 and CO2 over Ni/KIT-6 was 99 and 99 %, respectively. The superior catalytic behavior of Ni/KIT-6 is closely related to the large-pore cubic Ia3d structure of KIT-6, which enhanced dispersion of Ni nanoparticles, reduced carbon deposition, and increased diffusion of reactant and products.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Presents a general approach for the direct determination of three-dimensional mesoporous structures by electron microscopy. How mesostructured composite materials are obtained; Interest in three-dimensional mesopourous materials obtained by removing the organic phase for applications such as catalysis and chemical sensing or separation; Reports on high-resolution details of cage and pore structures of periodically ordered mesoporous materials which reveal a highly ordered dual micro- and mesoscale pore structure.

Nanometer-sized (below 100°nm) bimodal mesoporous aluminosilicate molecular sieves (NBMAS) are obtained by using sol–gel method and cetyltrimethylammonium bromide (CTAB) as the structure-directing agent. Ordering-packed framework mesopore is created within the colloidal particles by the templating function of surfactant CTAB and disordered textual pore is formed by the aggregation of colloidal particles as an inter-particle pore. As a result of the special properties of the present material, the hydrothermal stability and catalytic life of the material is highly improved in the catalytic cracking reactions. ZSM-5, normal AlMCM-41 and amorphous alumina–silica with nanometer particle size were used in the catalytic cracking process for comparing purpose. [Copyright &y& Elsevier]

Abstract: Mesoporous silica KIT-6-, SBA-15-, and MCM-41-supported Ni catalysts (Ni/KIT-6, Ni/SBA-15, and Ni/MCM-41) were prepared via impregnation method and studied for CO2 reforming of CH4. The catalysts were characterized by X-ray diffraction analysis, N2 physisorption measurements, scanning electron microscopy, transmission electron microscopy, and temperature-programmed oxidation (O2-TPO). The Ni/KIT-6 catalyst exhibited higher catalytic activity and long-term stability compared with Ni/SBA-15 or Ni/MCM-41. The conversion of CH4 and CO2 over Ni/KIT-6 was 99 and 99 %, respectively. The superior catalytic behavior of Ni/KIT-6 is closely related to the large-pore cubic Ia3d structure of KIT-6, which enhanced dispersion of Ni nanoparticles, reduced carbon deposition, and increased diffusion of reactant and products.Graphical Abstract: [ABSTRACT FROM AUTHOR]

• Highly ordered mesoporous WOx/SnO2 catalysts have been applied to the glycerol acetalization reaction. • Mesoporous WOx/SnO2 catalysts exhibited excellent catalytic performance in batch-type and continuous flow-type processes for catalytic synthesis of solketal from glycerol. • In a batch type process, 100% glycerol conversion and a solketal yield of 97.4% were achieved. Highly ordered WO x /mesoporous SnO 2 (WO x /meso‑SnO 2) catalysts with varying WO x loadings of (5 ∼ 20) wt% displaying excellent catalytic performance were demonstrated in the acetalization of glycerol with acetone. The synthesized catalysts were analyzed using various techniques including X-ray diffraction, N 2 -isotherm, electron microscopy, H 2 temperature programmed reduction, raman spectroscopy, and thermogravimetric analysis. For the acetalization of glycerol with acetone, the most active catalyst was found to be WO x /meso‑SnO 2 with 20 wt% WO x , and the maximum conversion of glycerol (100%) was obtained after 2 h at 20 °C, providing 97.4% selectivity (97.4% yield) for the five-membered product (solketal), due to the presence of a large number of acidic sites on the surface of the catalyst. The catalytic activity of 20 wt% WO x /meso‑SnO 2 was also studied in a flow reactor. Tests were carried out at 30 °C, acetone/glycerol=30, WHSV=(4 or 8) h −1, and atmospheric pressure for 24 h. The catalytic results showed that, when the WHSV was 4 h −1, after 24 h of time-on-stream, both the glycerol conversion of (100 to 97.9)% and solketal yield of (97.5 to 93.6)% slightly decreased. This result suggests the potential of the 20 wt% WO x /meso‑SnO 2 catalyst for the industrial acetalization of glycerol. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Pt/C catalyst was prepared by the formic acid reduction method (FARM) using mesoporous carbon supports with submicron-scale particle size, which was synthesized by the nano-replication technique using mesoporous silica (MSU-H) as templates. The average size of the Pt particles, calculated from the Pt(111) peak by Scherrer equation, was found to be 3.3nm. The chemical stabilities of Pt/C catalysts and polymer-coated Pt/C catalysts were examined in distilled water and in strong acidic solutions such as H2SO4 and HClO4. The release amount of Pt in distilled water was found to be at trace levels (<3ppb), which is close to the detection limits of ICP-AES. However, the Pt release greatly increased with time in both H2SO4 and HClO4 solutions and reached a few percent levels in a week. On the other hand, a PVP/PEI-coated Pt/C catalyst showed much better stability that the Pt release was about 0.5% in 3M HClO4 for a week, compared with that of a pristine Pt/C catalyst. [Copyright &y& Elsevier]

Abstract: Highly efficient catalytic carbon–carbon bond-forming reactions between aryl chlorides and Grignard reagents have been achieved using nickel (II) ion on nanoporous carbon. The catalytic activities in these reactions were so high that the effects of preparation, reduction, and phosphines could not be observed. No positional effect in the substrates was monitored. Increased formation of homocoupling products with functionalized substrates was also observed and a plausible explanation based on the competitive adsorption between substrates and Grignard reagents was proposed. [Copyright &y& Elsevier]

Abstract: Three catalysts, 1wt.% Pt/Al2O3, 20wt.% Cu/Al2O3, and 1wt.% Pt–20wt.% Cu/Al2O3 were evaluated for the oxidation of NO by O2 and the selective catalytic reduction (SCR) of NO x by NH3 in the absence and presence of H2O. The Pt/Al2O3 catalyst exhibited the largest values in NO oxidation efficiency and NO x removal efficiency among the three catalysts. The presence of H2O caused a drop in the NO oxidation and the SCR activities. The SCR performance was significantly improved when Pt/Al2O3 and Cu/Al2O3 catalysts were employed sequentially in a reactor. The highest SCR performance was achieved using two separate stages: oxidation of NO by O2 over the Pt/Al2O3 catalyst followed by reduction of NO2 by NH3 over the Cu/Al2O3 catalyst. Under the condition with H2O, the two-stage catalyst system showed NO x removal efficiency over 80% at low temperatures below 200°C, which was the highest value among the catalyst systems used in this study. The physical and chemical properties of the catalysts were determined using nitrogen adsorption, XRD, TPR, and pulse CO chemisorption experiments. [Copyright &y& Elsevier]

Catalytic etherification of 2-naphthol with ethanol has been carried out over a series of solid-acid catalysts such as H-Beta, H-MOR and H-ZSM-5 using a flow-type reactor. H-Beta zeolite shows higher conversion and catalytic stability than other catalysts for the production of 2-naphthyl ethyl ether, which may be correlated to the amount and strength of acid sites. H-Beta zeolites with different Si/Al ratios show that conversion decreases with increasing Si/Al ratios. The NH3-TPD profiles indicate that the weak acidity decreases more sharply with increase in Si/Al ratios, compared with the strong acidity. The influences of ethanol/2-naphthol molar ratios, reaction temperature, and space velocity with respect to catalytic activities are investigated for H-Beta zeolite in the present work. [Copyright &y& Elsevier]