Carbon plays a dual role as a catalyst or a catalyst support for chemical and enzymatic biomass transformation reactions due to its large specific surface area, high porosity, excellent electron conductivity, and relative chemical inertness. Advantageously, carbon materials can be prepared from residual biomass, an attractive property for decreasing the so-called “carbon-footprint” of a biomass transformation process. Carbon can be chemically functionalized and/or decorated with metallic nanoparticles and enzymes to impart or improve novel catalytic activity. Sulfonated porous carbon materials exhibit high reactivity in diversified catalytic reactions compared to their nonporous counterparts. However, the SO3H groups prevent the incorporation of hydrophobic molecules into the bulk, thereby causing hydrophobic acid-catalyzed reactions to proceed only on the surface. Metal and enzymatic catalysts on carbon supports have significant advantages over other oxide materials for different types of reactions. The ...

Carbon Materials as Catalyst Supports and Catalysts in the Transformation of Biomass to Fuels and Chemicals

Catalytic applications of Layered Double Hydroxides (LDH) or anionic clays have for a long time focused on the condensation reactions carried out with mixed oxides obtained by calcinations of Mg/Al LDH. However, the versatile character of materials prepared from these LDH exhibiting Lewis or Bronsted type basic sites has recently been underlined, and led us to contemplate extended applications in clean industrial processes. Moreover, due to their wide variety of compositions, LDH are also attractive precursors of multicomponent nanostructured catalysts. They give rise to supported metal catalysts whose metal support interaction and cooperation can be fine-tuned, as illustrated in pertinent case studies such as the hydrogenation of nitriles and the “one-pot” synthesis of methyl isobutyl ketone from acetone.

Catalysis by hydrotalcites and related materials

https://ris.utwente.nl/ws/files/6739600/Beenackers93mass.pdf

Mass transfer in gas-liquid slurry reactors

Primary or alkylated amines are important chemicals and intermedi-ates. N-Alkylamines are used without further transformation as surface-active agents. Aliphatic primary diamines polymerize with aliphatic diacids to give linear polyamides which have conquered a large place in textile and mechanical industry [11. Mono- and polyamines are produced by catalytic hydrogenation of the corresponding nitriles [2]. In particular this pathway to hexamethylenediamine has been made easier since the synthesis of adi-ponitrile by hydrocyanation of butadiene was made possible [3]. The spec-ifications for production of amines are often very drastic from the point of view of purity, in particular for the diamines used in the textile industry. Thus the stress is put on selectivity of the reaction and most of industrial processes have a yield approaching stoichiometry. It exists few reviews on reduction of nitriles [4, 51, the literature dealing with this type of reaction being mostly published in patents [6–91, an...

Homogeneous and heterogeneous hydrogenation of nitriles in a liquid phase: chemical, mechanistic, and catalytic aspects

A study of the hydrodeoxygenation (HDO) of 4-methylphenol over unsupported, low-surface-area MoS2, MoO2, MoO3, and MoP catalysts is reported. With the exception of MoO3, the catalysts had the same physicochemical properties before and after the 5 h reaction at 623 K and 4.40 MPa H2. The used MoO3 was partially reduced to a mixed oxide containing Mo4O11, MoO2, and Mo. Compared to the unused MoO3, the used MoO3 CO uptake increased by a factor of 100 following the reaction. The partially reduced Mo oxide catalyst had a high conversion for the HDO of 4-methylphenol because of Bronsted acid sites and the formation of anionic vacancies. The catalyst turnover frequency (TOF) based on CO uptake for the HDO of 4-methylphenol decreased in the order MoP > MoS2 > MoO2 > MoO3, while the activation energy increased in the order of MoP < MoS2 < MoO2 < MoO3. The activity trends correspond to the increased electron density of the Mo among the catalysts. Two primary reactions, C−O hydrogenolysis to yield toluene and satura...

Hydrodeoxygenation of 4-Methylphenol over Unsupported MoP, MoS2, and MoOx Catalysts†

Raney-nickel catalyzed hydrogenations: Gas-liquid mass transfer in gas-induced stirred slurry reactors

Hydrogenation of adiponitrile catalyzed by Raney nickel use of intrinsic kinetics to measure gas-liquid mass transfer in a gas induced stirred slurry reactor

E. Dietrich

Papers

Raney-nickel catalyzed hydrogenations: Gas-liquid mass transfer in gas-induced stirred slurry reactors

Hydrogenation of adiponitrile catalyzed by Raney nickel use of intrinsic kinetics to measure gas-liquid mass transfer in a gas induced stirred slurry reactor