Catalysis Letters

http://link.springer.com/journal/10562

List of Papers (Total 181)

Effect of Silver Addition to LaFeO3 Perovskite on the Activity of Monolithic La1−xAgxFeO3 Perovskite Catalysts in Methane Hexane Oxidation

La1−xAgxFeO3 (x = 0.05–0.25) perovskites deposited on a honeycomb-shaped monolithic metallic support were used as catalysts for the total oxidation of hydrocarbons. Monolithic catalysts were prepared by washcoating honeycomb substrates with lanthanum-stabilized γ-Al2O3, on which La1−xAgxFeO3 was deposited. Catalysts with La1−xAgxFeO3 perovskites show higher activity for methane...

Placing Ni(II) Ions in Various Positions In/On Layered Double Hydroxides: Synthesis, Characterization and Testing in C–C Coupling Reactions

Ni(II)-containing layered double hydroxides (LDHs) were synthesized with various methods with the intention of placing the Ni(II) ions in different positions in/on the LDH. Ni(II) was introduced as a lattice-modifier into CaAl-, CaFe- and MgAl-LDHs or in the interlayer space in form of a complex anion or as the divalent component of NiAl-LDH or as surface dopant. The materials...

Pd Supported IRMOF-3: Heterogeneous, Efficient and Reusable Catalyst for Heck Reaction

IRMOF-3 with a high surface area prepared by a hydrothermal method was used for deposition of Pd(OAc)2 on IRMOF-3 particles. The final catalyst was characterized with FT-IR, nitrogen physisorption, thermogravimetry, scanning electron microscopy, transmission electron microscopy combined with energy dispersive X-ray analysis, wide angle X-ray diffraction spectroscopy and X-ray...

On Apparent Activation Energy of Structure Sensitive Heterogeneous Catalytic Reactions

The notion of apparent activation energy is discussed in relation to structure sensitivity of complex heterogeneous catalytic reactions comprising several steps. The cases of nonuniform surfaces (intrinsic and induced) are considered, showing that the apparent activation energy depends on the cluster size and surface coverage. The theoretical analysis of the apparent activation...

Single-Atom Catalysis: How Structure Influences Catalytic Performance

It now seems clear that supported metal adatoms can be effective catalysts for some reactions, but how to make best use of this phenomenon remains an open question. Most studies to date have focussed on synthesizing stable “single-atom” variants of functioning supported nanoparticle systems, but there is mounting evidence that the properties of supported adatoms do not scale from...

Aldol Condensation of Cyclopentanone with Valeraldehyde Over Metal Oxides

Kinetics of the cross aldol condensation of valeraldehyde with cyclopentanone was investigated in a batch reactor under atmospheric pressure at 130 °C using heterogeneous metal modified oxides, such as CeO2–MgO, FeO–MgO, FeO–CaO as well as pristine CaO as catalysts. The catalysts were prepared either by evaporation impregnation or deposition precipitation methods and...

Improved Oxygen Reduction Activity of Transition Metal-Chelating Ordered Mesoporous Carbon Fuel Cell Catalysts by Milder Template Removal

In the synthesis of iron-chelating ordered mesoporous nitrogen-functionalized carbon (Fe–OMC) catalysts, the removal of the silica template is a crucial and critical step. The silica removal method used today for the Fe–OMCs is based on the very toxic hydrofluoric acid (HF), which usage should be limited where possible. Therefore, the aim of this study is to establish a mild...

The role of impurities in the La2O3 catalysed carboxylation of crude glycerol

The direct carboxylation of crude glycerol, obtained as a by-product of bio-diesel synthesis, with CO2 has been investigated over lanthanum oxide as a heterogeneous catalyst for the first time. Adiponitrile is employed as a dehydrating agent in order to shift the reaction equilibrium to the product side. The selectivity of the reaction towards glycerol carbonate when using crude...

Preparation of Betulone Via Betulin Oxidation Over Ru Nanoparticles Deposited on Graphitic Carbon Nitride

Derivatives of betulin obtained by oxidation have broad pharmacological applications, demonstrating anti-inflammatory, antioxidant, hepatoprotective, and anticancer activity. Ru supported catalysts based on graphitic carbon nitride or N-doped carbon were prepared via a mild reduction of the initial Ru precursor with hydrazine. These catalysts along with Ru supported on carbon...

Combining Chemical and Biological Catalysis for the Conversion of Hemicelluloses: Hydrolytic Hydrogenation of Xylan to Xylitol

The conversion of xylan to xylitol is commonly realized via the two separate process steps hydrolysis and hydrogenation (or fermentation). Recent research activities aim at developing one-pot processes to facilitate this conversion to save resources and operation time. To avoid hazardous chemicals like liquid acids for the initial xylan hydrolysis, enzymes are a suitable green...

Nanostructured Potassium-Manganese Oxides Decorated with Pd Nanoparticles as Efficient Catalysts for Low-Temperature Soot Oxidation

Two nanostructured potassium–manganese oxides, with a layered (OL) and tunneled structure (OMS-2), were synthesized and their surface decorated with 1% Pd. All prepared samples were characterized by means of X-ray diffraction, Raman spectroscopy, N2-BET specific surface area analysis, TPR, SEM/TEM. Catalytic activity in soot combustion in different reaction conditions was...

Early Transition Metal Doped Tungstite as an Effective Catalyst for Glucose Upgrading to 5-Hydroxymethylfurfural

Glucose valorization to 5-hydroxymethylfurfural (HMF) remains challenging in the transition towards renewable chemistry. Lewis acidic tungstite is a viable, moderately active catalyst for glucose dehydration to HMF. Literature reports a multistep mechanism involving Lewis acid catalyzed isomerization to fructose, which is then dehydrated to HMF by Brønsted acid sites. Doping...

Impregnated and Co-precipitated Pd–Ga2O3, Pd–In2O3 and Pd–Ga2O3–In2O3 Catalysts: Influence of the Microstructure on the CO2 Selectivity in Methanol Steam Reforming

To focus on the influence of the intermetallic compound—oxide interface of Pd-based intermetallic phases in methanol steam reforming (MSR), a co-precipitation pathway has been followed to prepare and subsequently structurally and catalytically characterize a set of nanoparticulate Ga2O3- and In2O3-supported GaPd2 and InPd catalysts, respectively. To study the possible promoting...

Heterogeneous Surfaces as Structure and Particle Size Libraries of Model Catalysts

Different types of model catalysts and their characterization by a wide range of surface analysis techniques have been a successful approach to determine the activity and/or selectivity of catalytic processes, with the effects of surface structure and particle size being key aspects. In recent years, new types of model systems, exhibiting regions of different crystallographic...

Chemical Reactions at Isolated Single-Sites Inside Metal–Organic Frameworks

Isolated, coordinatively unsaturated metal sites within metal–organic framework (MOF) materials feature interesting chemical properties and offer applications as single-site catalysts. Here, we report on the recent progress in providing fundamental insight into chemical reactions occurring inside MOFs. In addition to the common form, powders, we discuss the potential of MOF thin...

Gold as a Catalyst for the Ring Opening of 2,5-Dimethylfuran

The epoxidation of 2,5-dimethyl furan leads to the production of hex-3-ene-2,5-dione via a ring opening rearrangement reaction. A second epoxidation reaction could then enable a further ring closing rearrangement to form 4-hydroxy-2,5-dimethyl-3-furanone (furaneol). In this paper we report the use of gold and gold palladium supported on graphite and titania as catalysts for the...

MCF Material as an Attractive Support for Vanadium Oxide Applied as a Catalyst for Propene Epoxidation with N2O

Vanadium modified mesocellular silica foams (MCF) materials (V content ca. 3 and 5 wt%) prepared by the impregnation method show mainly isolated or low-polymeric VOx species, which was confirmed by means of Raman spectroscopy and DR UV–Vis. Textural measurements, and also XRD and TEM results indicate that the characteristic mesocellular structural features of MCFs are preserved...

Methane Cracking over Cobalt Molybdenum Carbides

The catalytic behaviour of Co3Mo3C, Co6Mo6C, Co3Mo3N and Co6Mo6N for methane cracking has been studied to determine the relationship between the methane cracking activity and the chemical composition. The characterisation of post-reaction samples showed a complex phase composition with the presence of Co3Mo3C, α-Co and β-Mo2C as catalytic phases and the deposition of different...

About the Mechanism of Methanol Conversion on Zeolites

Time- and space resolved selectivity in methanol conversion on zeolites has been investigated and exploited for insight about the reaction mechanism. Particular focus is directed to constraints on diffusion and reaction provided by the pore structure. 3 zeolites with well-ordered voids and channels of different size have been used comparatively. Novel experimental tools have been...