Manufacture Porous Materials by Dabco-Based Lonic Liquid

The long-chain ionic liquid (IL) hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide was used as a template to prepare the hexagonally ordered siliceous mesoporous molecular sieve MCM-41 as well as the disordered mesoporous molecular sieve designated as KIT-1. The synthesized products were studied via X-ray diffraction (XRD), Fourier transform infrared (FTIR) and N2 adsorption-desorption analysis. The surface area (BET), pore volume, and pore diameter (BJH) are determined. These kind of ILs that have DABCO (1,4-diazabicyclo[2.2.2]octane) in their structures, were prepared with an easy method. When the two templates, cetyltrimethylammonium bromide (CTAB) and IL, have the similar structures, MCM-41 mesoporous molecular sieve produced with more ordered, uniform mesoporous channel and high surface area in comparison to without IL. When just IL used instead of CTAB, the KIT-1 with non-uniform mesoporous was obtained. Here we prepared the KIT-1 mesoporous molecular sieve with IL without CTAB but it seems, using dual template with changing IL structures in fabricated of molecular sieve provide new opportunity to design targeted adsorbents and catalysis.

Synthesis and Characterization of MCM-48 Molecular Sieves with High Specific Surface Area

The hydrothermal synthesis of MCM-48 molecular sieves with CTAB and TEAOH as dual template agents and alkaline silica sol as silicon source has been systematically studied. The samples prepared at different crystallization temperature and time were analyzed by XRD, IR, nitrogen adsorption and desorption. The result shows that the best crystallization temperature and time are 100°C and 48h, respectively. According to BJH algorithm, the specific surface area of the sample is 1088 ~ 1669 m2/g, the pore size is 2.48 ~ 2.54 nm, and the pore volume is 1.2064 ~ 1.263 0cm3/g. Because it has high specific surface area, it can be widely used in catalytic adsorption, environmental engineering, biomedicine and other fields. Keywords: MCM-48; mesoporous molecular sieve; high specific surface area; dual template agents; alkaline silica sol

Catalytic Transfer Hydrogenation of Biomass Derived 5-Hydroxymethylfurfural into 2,5-Dimethylfuran in a Methanol Medium

The hydrogenation of HMF has been conducted in a methanol medium, which served as hydrogen donor and solvent. Without any additive, HMF was hydrogenated to 2,5-dimethylfuran (DMF) with complete conversion and selectivity (64%) using well-ordered mesoporous MCM-41 with high nickel content as catalyst at 190 °C in 5 h. Two kinds of mesoporous molecular sieve catalysts were prepared by impregnation and in-situ synthesis. Different reaction parameters such as the amount of Ni, reaction time and temperature were optimized to achieve the highest catalytic activity. Moreover, the plausible reasons for the difference in catalytic effects between the two types of catalysts were also discussed.

Тemplate synthesis of multidimensional porous silica

Isothermal data of superficial tension of solutions of surfactant mixture and low-temperature nitrogen sorption of multidimensional porous silica received by template synthesis prove complementarity of its properties and properties of SAA micelles. The measured isotherms of gas sorption belong to IV Type inherent in mesoporous adsorbents. The BET specific surface area is 600–800 m2/g, and the Gurvich pore volume is 0.7–1.0 cm3/g. With increase in mole fraction of nonionic component these values decrease, the ordered texture of SiO2, characteristic of MCM-48 mesoporous molecular sieve, collapses, d211-spacing becomes < 3.31 nm, and NLDFT distribution is transformed from monomodal to polymodal one.

SBA-15 as a Support for Effective Olefin Metathesis Catalysts

Olefin metathesis is the catalytic transformation of olefinic substrates, finding a wide range of applications in organic synthesis. The mesoporous molecular sieve Santa Barbara Amorphous (SBA-15) has proven to be an excellent support for metathesis catalysts thanks to its regular mesoporous structure, high BET area, and large pore volume. A survey of catalysts consisting of (i) molybdenum and tungsten oxides on SBA-15, and (ii) molybdenum and ruthenium organometallic complexes (Schrock and Grubbs-type carbenes) on SBA-15 is provided together with their characterization and catalytic performance in various metathesis reactions. The comparison with catalysts based on other supports demonstrates the high quality of the mesoporous molecular sieve SBA-15 as an advanced catalyst support.