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Showing 1 to 20 of 24 for “"Hydrotalcite"”.
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Intercalation d'anions organiques dans des composés lamellaires de type hydrotalcite.
New hydrotalcite-like intercalation products have been prepared. Organic molecules were incorporated by different methods. The first method consisted of the direct intercalation of organic species during the metal hydroxide precipitation process. The second method was based on an ionic exchange …
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The use of hydrotalcite derived catalyst precursors in the Fischer-Tropsch synthesis
… alkali onto the support material [Dry,1981 ]. Hydrotalcites have been shown to provide a high surface area basic support [Schaper, 1989]. Supporting the iron metal used in Fischer-Tropsch synthesis onto the basic hydrotalcite eliminates the problems associated with supported alkali promoted …
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Catalysts for H2 production
… from perovskite type compounds (PVK) and from hydrotalcite type precursors (HT); 2) Structured catalysts, i.e. catalysts supported on materials having high thermal conductivity (SiC and metallic foams). As regards the catalytic partial oxidation, the effect of the metal (Ni and/or Rh), the role …
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Studies of tartaric acid modified nickel supported catalysts for enantioselective hydrogenation reactions
… acid‐nickel supported catalysts, obtained from hydrotalcite‐like compound precursors, in the enantioselective hydrogenation of methyl acetoacetate to methyl 3‐hydroxybutyrate. Variables of reaction during modification such as pH and tartaric acid concentration, as well as Ni particle size above …
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Modification of clays with ionic liquids for polymer nanocomponents
… with layered double hydroxide clays, a synthetic hydrotalcite susceptible to exchange of its interlamellar carbonate ions with a variety of other anions, was selected. Reagents having anions differing in size and structure included two colorless ionic liquids ([Epty]^+[BF4]^- and …
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Entwicklung basischer Feststoffkatalysatoren für industrielle Anwendungen
… Mischoxide überführt. Die Mischoxide sowie die Hydrotalcite wurden mittels Elementaranalyse, Pulverröntgendiffraktometrie, gekoppelter TG/DSC/MS-Messungen und N2-Adsorptionsmessungen eingehend charakterisiert. Insgesamt konnte die Synthese von Hydrotalciten und Mischoxiden mit verschiedenen …
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Base stable and basic ionic liquids for catalysis
… liquids was achieved through the synthesis of hydrotalcite composites. The heterogeneous catalysts were used to promote Knoevenagel, aldol and dehydration reactions. The gels, silica spheres and hydrotalcite composites were recovered by filtration and re-used without a decrease in activity. …
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Investigation of adsorbent-based warm carbon dioxide capture technology for IGCC system
… The new sorbent performs better than synthetic hydrotalcite and K²CO³-promoted hydrotalcite in the temperature range of interest. To assess the applicability of CO₂ removal technology to IGCC via a warm pressure swing adsorption (PSA) process based on our newly invented sorbent which has good …
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Functionalization of nanoclays through exchange reactions
… MMT) and an anionic clay (hydrotalcite, HT) were treated with two phosphonium based ionic liquids (ILs) and a commercial corrosion inhibitor. Clay modification was examined by TGA, FTLR and WXRD. The cationic clay modified with both ILs had similar thermal stabilities since …
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Synthesis and characterization of polymer nanocomposites
… size, shape, aspect ratio and purity such as hydrotalcite (HT), sodium montmorillonite (MMT), single wall carbon nanotubes (SWNT) and fullerenes (FUL), at 5 and 10 wt% loading. Structural characteristics and mechanical, thermal and barrier properties of the nanocomposites were characterized by …
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Acid-base catalysts for polycondensation of acetaldehyde in flow
… pelletized Evonik P25 TiO₂ and an activated hydrotalcite-like compound (HTlc), to produce high molecular weight molecules in the transportation fuel range. The catalytic performance of these materials is evaluated in a gas phase, atmospheric flow system with a packed bed microreactor designed …
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Carbon Dioxide Capture with K-Promoted HTLC at High Temperature
… feasible options for CO2 capture. To this end, hydrotalcite-like compounds (HTlcs), when promoted with metal carbonate, such as K2CO3, have attracted considerable attention in the literature due to their reversible adsorption capacity for CO2 at elevated temperatures.</p> <p>The focus of this …
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Molecular Structure, Diffusion Dynamics and Hydration Energetics of Non-Confined Water and Water at Mineral Surfaces
… for brucite [Mg(OH)2], gibbsite [Al(OH)3], and hydrotalcite [Mg2Al(OH)6Cl·2H2O] will illustrate these effects for hydroxide phases, and results for talc [Mg3Si 4O10(OH)2] and muscovite [KAl2(Si 3Al)O10(OH)2] those for silicates. Topics highlighted include the transition from the first …
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Bimetallic Catalyst for Lignin Depolymerization
… catalyst with copper and nickel co-doped on a hydrotalcite support, testing the hypothesis that a bimetallic catalyst containing copper and nickel will have better reforming ability than a catalyst containing only nickel and will have better hydrogenolysis of aryl-ether ability than a catalyst …
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Layered Double Hydroxides and the Origins of Life on Earth
… whether this reaction also occurs with hydrotalcite itself, what is the minimum effective concentration of cyanide, and what can be learned about the products and how they compare with those reported at high HCN concentrations in the absence of catalyst.
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Study of controlled release of active pharmaceutical ingredients from functionalized nanoclays and polymer matrices
… which can be directly applied to carbonated hydrotalcite was used and successfully achieved API intercalations. During reconsitution of the clay, the crystalline APIs in the clay interlayer was apparently transformed in an amorphous state, and as a result it showed increased apparent …
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Degradation of polylactic acid in the presence of microsize and nanosize fillers
… (montmorillonite, MMT) and anionic (hydrotalcite, HT) clay micro- or nanocomposites based on semicrystalline and amorphous polymers and unmodified and organomodified as well as calcined or non-calcined clays at 5wt% concentration are produced by melt mixing. Depending on the clay …
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Stabilisation of clay subgrade soils using ground granulated blastfurnace slag
… aluminosilicate hydrate gel (C-A-S-H) and hydrotalcite type phase, and the clay-lime reaction to produce calcium silicate hydrate (C-S-H), (C-A-H) and (C-A-S-H). The NMR test results revealed that the aluminosilicate chain length (EL), the aluminium: silicate (Al/Si) ratio and the amount of …
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Effect of carbonation on bound chlorides in cementitious and alkali activated binders
… formation of Friedel’s salt and the structure of hydrotalcite to alkali activated fly ash and alkali activated metakaolin, chloride binding was mostly due to physical absorption. The influence of carbonation on the bound chlorides in different alkali activated systems is mainly on the chemical …
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The effect of nanoclays on the properties of aspirin modified enteric polymer prepared by hot-melt mixing
… are produced by incorporating a nanoclay, hydrotalcite (HT). The morphology of HT in the nanocomposites, originally a multilayer structure, is significantly changed with increasing ASP loading. ASP shows affinity to the Al and Mg ions of the HT layers, resulting in a change of the HT …
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