Abstract Mixtures of water and organic cosolvents (mixed solvent systems) play an important role in mediating acid-catalyzed biomass conversion reactions. A minimum amount of water is typically required to dissolve biomass-derived materials, while adding an organic cosolvent can enhance the rates and selectivities of the desirable, catalytic reaction steps. Understanding the molecular-level bases underlying

Abstract The impact of metal/oxide interfaces on the catalytic properties of oxide-supported metal nanoparticles is a topic of longstanding interest in the field of heterogeneous catalysis. The significance of the metal/oxide interaction has been shown to vary according to both the inherent reactivity of the metal nanoparticle and the properties of the oxide support, with effects such as the metal

Abstract The reactivity of methanol and methyl acetate mixtures over a HZSM-5 catalyst is studied over a period of 6 h at 350 °C, with small molecular weight olefins and aromatic compounds observed as reaction products. Post-reaction analysis of the catalyst shows the coke content to increase with methyl acetate content. Vibrational spectra (DRIFTS and inelastic neutron scattering, INS) indicate the

Abstract A mixed metal-oxide (NiAlOx) obtained from the annealing of a synthetic takovite clay, [(Ni6Al2(OH)16]CO3·4H2O, was used as a catalyst in the hydrodeoxygenation reaction of vanillin, as a model molecule, to simulate deoxygenation of lignin's moieties. The catalysts were characterized by XRD, TPR, XPS and textural analyses and were tested at between 413 and 573 K and 1.2 MPa H2, using a 300

Abstract Cuprous oxide (Cu2O) microspheres were synthesized through a simple chemical method by using ascorbic acid (AA) as reducing agent at room temperature and short reaction time. The influence of the reducing agent and ammonium hydroxide (NH4OH), as well as reaction time, on the morphology, size, and crystalline phase structure of Cu2O were explored. The obtained materials were characterized by

Abstract A serial of carbon modified Ag/TiO2 photocatalysts have been synthesized with different carbon content by a simple co-impregnation method. Here, 1-pentanol was used as carbon precursor. The carbon modified Ag/TiO2 nanocomposites were characterized by X-ray diffraction, raman spectroscopy, thermal gravity analysis, UV–vis diffuse reflectance spectra, photoluminescence, and X-ray photoelectron

Abstract Research evolved using nanoparticles synthesized and characterized under reaction conditions opened the door to study all three fields of catalysis: heterogeneous, homogenous, and enzyme. Fundamental studies of catalytic reactions ranging from hydrogenation to understand Fischer-Tropsch synthesis and isomerization ultimately led to the integration of three fields of catalysis. Our recent work

Abstract In the present work, we compared the hydrodesulfurization (HDS) behavior of NiMo catalysts supported on titania-based nanomaterials (hydrogen titanate nanotubes and nanotubes decorated with anatase nanocrystals), with that of the reference NiMo/γ-alumina and NiMo/TiO2 samples. Supports and calcined catalysts were characterized by nitrogen physisorption, powder XRD, UV–Vis diffuse reflectance

Abstract Cu(Fe)-containing zeolites are promising catalysts for biomimetic functionalization of light hydrocarbons. Catalysts with various copper states have been elaborated and studied in the peroxide oxidation of methane to methanol and formic acid. ICP-AES, UV–vis DR, EPR, NH3-TPD, H2-TPR, and N2 adsorption techniques were used for the characterization of the Cu(II) states, the textural, acidic

Abstract The kinetics of the low-temperature forward water gas shift (LT-WGS) reaction have been studied over a 2 wt% Au/CeZrO4 (Au/CZO) catalyst using both thermal and dielectric barrier discharge plasma heterogeneous catalyst systems. Using the energy density (ε), the apparent activation energy has been calculated under plasma and thermally activated conditions. A substantially lower apparent activation

Abstract The co-adsorption of hydrogen and carbon monoxide on Pd3Ag(111) alloy surfaces has been studied as a model system for Pd-Ag alloys in membrane and catalysis applications using periodic density functional theory calculations (PW91-GGA). We explored the effects of Pd–Ag surface composition, since segregation of silver towards and away from the surface has been suggested to explain the experimentally

Abstract Octahedral molecular sieves (OMS-2) are an interesting form of manganese oxide with a 2 × 2 edge sharing tunnel structure and a cation positioned inside. Cryptomelane is an OMS-2 material with K+ cations within the crystalline tunnel and has been widely used in catalytic oxidation reactions, due to a mixed valency of Mn3+ and Mn4+ cations. Cryptomelane (K-OMS-2) can be modified by structural

Abstract In the present work, a kinetic study and optimization of the process of spruce wood peroxide oxidation in “acetic acid–water” medium in the presence of suspended TiO2 catalyst at temperatures 70–100 °C were accomplished for the first time. The effect of wood species and organic solvent nature on the features of the processes of catalytic peroxide fractionation of wood biomass on microcrystalline

Abstract The preparation, characterisation and application of two catalysts active in selective hydrogenation (Pt/TiO2) and esterification (mesoporous SiO2 material modified with tethered sulfonic acid groups) reactions is described. The catalysts are characterised using a range of spectroscopic, microscopic and adsorption techniques. Pt/TiO2 catalysts promote valeric acid (a cellulose derived platform

The original version of this article unfortunately missed to include the link to the Supplementary material. The authors would like to correct the error with this erratum.

Abstract van der Waals (vdW) corrected periodic density functional theory (DFT) calculations and microkinetic modeling were employed to elucidate the mechanism and energetics of dehydrogenation of tetrahydropyrrole, a model organic hydrogen carrier, on Pt(111). The overall dehydrogenation is endothermic while individual dehydrogenation steps can be endothermic or exothermic. The calculations indicate

Abstract Ceria-tin (CS) oxide catalytic systems were synthesized using cetyltrimethylammonium bromide (CTAB) and Pluronic 123 (P123) templates and modified with CuOx using two techniques: the “one-pot” method (Cu addition during CS synthesis) and the post-impregnation (IM). The catalysts were tested in CO oxidation in the stoichiometric CO/O2 mixture balanced with He. XRD, TPR, Raman spectroscopy,

Abstract The effect on the incorporation of zinc of three zeolites TNU-9, MCM-22, and MCM-68 was investigated. The physico-chemical properties of zeolites were studied by X‐ray diffraction, N2-adsorption, temperature‐programmed desorption of NH3 (TPD), nuclear magnetic resonance of 27Al and 29Si (MAS NMR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Then all the samples

Abstract The strong Mo–N bond restrains the catalytic activity of metallic Mo in ammonia synthesis. In this study, the semi-empirical calculations in conjunction with the density functional theory calculations, Brønsted–Evans–Polanyi relationship and microkinetic modeling were used to evaluate the rate of ammonia synthesis on model active sites of Mo-based alloys, nitrides, and clusters with a modified

Abstract A series of TiO2 photocatalysts loaded with various metals (Pt, Pd, Ni, and Cu) were prepared by using the wet impregnation method. Their physicochemical properties were studied by using XRD, BET, TPR-H2, FTIR and TPD-NH3/CO2 techniques. The photocatalytic activity of samples was investigated in the gas-phase reduction of carbon dioxide under continuous flow operation mode. Among all investigated

Abstract Platinum nanoparticles supported on MgO, Al2O3, ZrO2, TiO2 were utilized for monoterpenoid oximes hydrogenation. Monocyclic menthone and carvone oximes synthesized from bio-derived monoterpenoids with a different structure were used to explore the effect of substrate structure on the reaction regularities. The oximes hydrogenation was carried out under hydrogen atmosphere at 100 °C using methanol

Abstract The ethanol dehydration and subsequent ethylene oligomerization to short-chain olefins using catalysts based on ZSM-5 zeolite was studied in detail. P, Fe, and Ni were added by incipient wetness impregnation on zeolites with two SiO2/Al2O3 molar ratios (50 and 80). The catalysts were characterized by N2 adsorption–desorption, XRD, SEM–EDX, FTIR spectroscopy of adsorbed pyridine, and XPS techniques

Abstract In this contribution we provide details of the BP-Johnson Matthey proprietary Fischer–Tropsch technology and the advanced CANS reactor and catalyst system. The advanced CANS catalyst carrier reactor provides superior heat transfer, reduced pressure drop and higher productivity that lead to major economic savings. Fundamental understanding of catalyst behaviour is also key to obtaining a catalyst

Abstract This work reports on the synthesis of photocatalysts in thin film form of TiO2 modified with Sn, Eu as well as Sn and Eu simultaneously. The obtained films were characterized by X-Ray Photoelectron Spectroscopy, Raman Spectroscopy and Ultraviolet–Visible Spectroscopy, in order to obtain information on their chemical composition, vibrational features and optical properties respectively. Chemical

Abstract This work is devoted to kinetic modelling of levulinic acid (LA) hydrogenation to gamma-valerolactone (GVL) in aqueous medium in a batch mode using 5%-Ru/MN100 catalyst, which comprises Ru dioxide nanoparticles confined in polymeric network of hyper-crosslinked polystyrene of MN100 type. Kinetic models of liquid-phase hydrogenation of LA to GVL were proposed based on Langmuir–Hinshelwood and

Abstract A series of Mn5Co1Ox catalysts calcined at different temperatures in the range of 400–800 °C were synthesized by coprecipitation of manganese and cobalt nitrates and tested in the oxidation of CO. The specific surface area, structure, and chemistry of the catalysts were studied. In addition, the reduction of the catalysts by hydrogen was studied using in situ X-ray diffraction and temperature-programmed

Abstract Two types of nickel-modified Cd1−xZnxS-based photocatalysts, CdxZn1−xNiySy+1 (mol% Ni = 0.05–0.5; x = 0.8) and yNiS/CdxZn1−xS (mol% Ni = 0.1–1.0; x = 0.8), were prepared via a simple two-stage technique. The samples were characterized by XRD, UV–vis spectroscopy, and XPS techniques. The activity of the synthesized photocatalysts were tested in the gas-phase photocatalytic reduction of CO2

Abstract The present work studies the effect of zirconium dioxide addition in hydrozincite (Zn5(OH6)(CO3)2). The composites samples shows an efficient photocatalytic activity for H2 production under UV light irradiation and employing methanol as a sacrificial reagent. The composites were synthesized in one-pot method, dried to 100 °C and characterized by X-ray diffraction (XRD), Fourier transform infrared

Abstract Noble-metal nanocrystals with structural features such as high-index facets and twin defects on the surface are desirable for various catalytic applications. Here we report an aqueous route to the facile synthesis of Pd–M (M = Pd, Pt, and Au) decahedra covered with concave facets by controlling the deposition and diffusion of M atoms on Pd decahedral seeds. Our mechanistic studies indicate

Abstract Mechanism of ethanol partial oxidation into syngas over catalysts based on mesoporous MgAl2O4 spinel loaded with fluorite PrCeZrO or spinel MnCr2O4 oxides and promoted by Ru + Ni was studied by in situ FTIRS and 18O SSITKA. Surface species (ethoxy, adsorbed ethanol, acetaldehyde, acetate, etc.) were identified and their thermal stability and reactivity were estimated. Analysis of kinetics

Abstract The oxidation of propane was studied over Ni foil, a thick Ni/Si film, and a thin Ni/Si film in a flow reactor under oxygen-deficient conditions at a total pressure near 1 mbar. The thickness of the foil was 125 µm, while the thickness of the films was 20 and 1.5 µm, respectively. It was shown that regular self-sustained reaction-rate oscillations arise only over the Ni foil and the thick

Abstract The regular reaction rate oscillations were observed by mass-spectrometry in the oxidation of propane over the Ni foil. CO, CO2, H2, and H2O were detected as products. The oscillations of products and reactants in the gas phase were accompanied by the oscillations of the catalyst temperature. It was shown by using isotopic labeling 18O2 that CO and CO2 formed simultaneously by the propane

Abstract Linear α-olefins or LAOs are produced by the catalytic oligomerisation of ethylene on a multimillion ton scale annually. A range of LAOs is typically obtained with varying chain lengths which follow a distribution. Depending on the catalyst, various types of distributions have been identified, such as Schulz–Flory, Poisson, alternating and selective oligomerisations such as ethylene trimerisation

Abstract In this work series of photocatalysts based on ZnO modified by Au and Ag2CO3 addition and Ag–TiO2 materials were synthesized and evaluated in the treatment of handicrafts factories wastewater and water samples taken from a highly polluted river. In general, it was found that ZnO series were more effective in the bacteria elimination than the commonly used TiO2 semiconductor. It was also observed

Abstract The aerobic oxidation of cinnamyl alcohol in toluene under autoxidation conditions has been studied using a range of 1 wt% Au–Pd/TiO2 catalysts. The catalysts have been studied to determine the effect of preparation method (impregnation and sol immobilisation) and metal ratio on the conversion of cinnamyl alcohol and the selectivity to cinnamaldehyde. The catalysts prepared by sol-immobilisation

Abstract An important decrease in the soot combustion temperature was observed by employing potassium and manganese on ZrO2 as support; significantly boosted soot combustion was obtained with the K/ZrO2 and Mn–K/ZrO2 catalysts for T50 at 295 and 240 °C, respectively. The enhanced catalytic activity by using the Mn–K/ZrO2 catalyst could be attributed to the alkaline metal ion, which improved the catalyst/soot

Abstract Pt catalysts supported on the commonly used supports Al2O3, SiO2 and on mesostructured silicates SBA-15 and MCM-48 were examined in the dehydrogenation of decalin, that is the promising liquid organic hydrogen carrier (LOHC). Synthesized catalysts were studied by low-temperature nitrogen adsorption, temperature programmed reduction, high-resolution transmission electron microscopy. The catalysts

Abstract Heavy crude oil enhanced into a lighter oil by hydrocracking process with nickel nanoparticles (Ni NPs) as catalysts. Ni NPs were synthesized by colloidal method (chemical reduction of metal salts). The reduction of nickel nitrate hexahydrate ((Ni(NO3)2·6H2O) was done using sodium borohydride (NaBH4) as a reducing agent in presence of polyvinylpyrrolidone which worked as a protective and stabilizing

Abstract In order to increase the catalytic activity of titanium dioxide (TiO2) under visible light, a method for the synthesis of a complex sandwich catalyst based on nanotubular and sol–gel TiO2 and colloidal cadmium sulfide (CdS) was developed. The use of titanium dioxide in the form of nanotubes allowed increasing the specific surface area of the catalyst, which is one of the main factors in increasing

Palladium has been shown to be an effective catalyst for chloroform hydrodechlorination, which serves as a promising treatment method for industrial chloroform waste. To investigate the structure sensitivity of this chemistry on Pd surfaces, we performed a density functional theory (DFT, GGA-PW91) study of the chloroform hydrodechlorination reaction on three distinct facets: Pd(111), Pd(100), and Pd(211)

Abstract Element selectivity and possibilities for in situ and operando applications make X-ray absorption spectroscopy a powerful tool for structural characterization of catalysts. While determination of coordination numbers and interatomic distances from extended spectral region is rather straightforward, analysis of X-ray absorption near-edge structure (XANES) spectra remains a highly debated and

Gold nanoparticles dispersed on MnOx/TiO2 were used to perform the oxidation of carbon monoxide at low temperatures. Remarkable dispersion of gold nanoparticles under hydrogen treatment was obtained, mainly in Au–MnOx/TiO2 catalysts with 2 wt% Au and 5 wt% Mn, where the Au nanoparticles displayed average sizes of 1–3 nm. The addition of Au nanoparticles to the MnOx/TiO2 catalysts promoted both the

Abstract The bimetallic Pd–Pt/Al2O3 supported catalysts with different Pd/Pt ratios have been prepared and studied in methane oxidation reaction. Comparison of their catalytic properties with those of monometallic Pd/Al2O3 and Pt/Al2O3 samples has shown that the bimetallic catalysts with a relatively low Pt loading (less than 0.4 mol%) are more active than the monometallic ones indicating the synergy

Abstract Oscillatory behavior during CO oxidation over a Ni foil in a continuous-flow catalytic reactor has been discovered in the reaction mixture containing CO excess at atmospheric pressure in the temperature range of 500–630 °C. The oscillations are accompanied by propagation of the oxidation and reduction fronts which were recorded by a photo–video camera. Dark fronts of the oxidized state appear

Three-way catalysts containing palladium and/or rhodium were prepared using γ­Al2O3 doped with lanthanum oxide as a support. All the samples were obtained by an incipient wetness impregnation of the support with an aqueous solution of nitrates. In order to investigate the metal–support interaction, the support was additionally calcined at 800 °C before the impregnation procedure. Characterization of

Abstract A series of bimetallic Pd–Zn catalysts supported on the carbon material Sibunit was synthesized for selective hydrogenation of acetylene. XRD, XPS, XAFS and TEM data revealed that the structure and dispersion of bimetallic particles in Pd–Zn/Sibunit samples depend on the molar ratio Pd:Zn. The active component of the Pd–Zn(1:0.25)/Sibunit sample is a substitutional solid solution. In the catalysts

The oxidation of glycerol represents both a viable route to catalytic upgrading of biomass and has become a model reaction for catalytic polyol oxidation. Gold and gold–palladium nanoparticle catalysts prepared by colloidal methods involving polymer additives have been extensively studied. However, the effect of residual polymer at the catalyst surface on reaction pathways has not been decoupled from

Herein, we have shown that the phase composition of molybdenum carbide catalysts has a pronounced effect on the pairwise hydrogen addition selectivity in the gas-phase propyne hydrogenation with parahydrogen. Molybdenum carbide catalysts were prepared using either the Pechini method or temperature-programmed reduction with CH4/H2 carburizing gas mixture. The structures of carbide catalysts were characterized

In this work, we report a series of novel nickel(II) dibromide and dichloride complexes with 2-iminopyridine and 2-iminoquinoline ligands bearing electron-withdrawing substituents (F, Cl, CF3), that have demonstrated high ethylene dimerization activity [up to 19.2 × 106 g of oligomers·(mol Ni)−1 h−1] in the presence of MAO or Et2AlCl, affording predominantly a mixture of 1-butene and cis- and trans-2-butene

Pulsed field gradient NMR diffusion measurements provide a non-invasive measure of the mass transport (self-diffusion) characteristics of liquids confined to porous catalyst materials. Here we explore the ability of this technique to probe the diffusive behaviour of a series of short-chain primary alcohols within a mesoporous catalyst support material; through the comparison of our results with highly

Catalytic partial oxidation (PO) of dimethoxymethane (DMM) to syngas was investigated in a fixed-bed continuous flow reactor under ambient pressure and at 250–500 °C over Pt-, Rh- and Ru-supported on Ce0.75Zr0.25O2–δ catalysts. The Pt catalyst was found to be the most active and selective. It provided complete conversion of DMM to gas mixture containing ˃ 60 vol% of H2 and CO at 400 °C, GHSV = 10,000 h−1

The Toe-to-Heel Air Injection (THAI) combined with a catalytic add-on (CAPRI, CATalytic upgrading PRocess In-situ) have been a subject of investigation since 2002. The major challenges have been catalyst deactivation due to coke deposition and low temperatures (~ 300 °C) of the mobilised hot oil flowing over the catalyst packing around the horizontal well. Tetralin has been used to suppress coke formation

With the passing of Frank Sidney Stone on 5 March 2018 in Dorset, England, the solid state chemistry and the catalysis scientific communities lost a highly respected elder statesman. Always a gentleman, he was pleasant, unassuming and very knowledgeable with what might be described as a serious sense of humour that made his speeches especially entertaining. He was born and based throughout his life

Carbon fiber-reinforced polymer (CFRP) materials are widely used in aerospace and recreational equipment, but there is no efficient procedure for their end-of-life recycling. Ongoing work in the chemistry and engineering communities emphasizes recovering carbon fibers from such waste streams by dissolving or destroying the polymer binding. By contrast, our goal is to depolymerize amine-cured epoxy

The principles, strengths and limitations of several nonlinear optical (NLO) methods for characterizing biological systems are reviewed. NLO methods encompass a wide range of approaches that can be used for real-time, in-situ characterization of biological systems, typically in a label-free mode. Multiphoton excitation fluorescence (MPEF) is widely used for high-quality imaging based on electronic

Cyclic carbonates are valuable chemicals for the chemical industry and thus, their efficient synthesis is essential. Commonly, cyclic carbonates are synthesised in a two-step process involving the epoxidation of an alkene and a subsequent carboxylation to the cyclic carbonate. To couple both steps into a direct oxidative carboxylation reaction would be desired from an economical view point since additional

Electrolysis of water is key technology, not only for clean energy production, but to ensure a continued supply of hydrogen beyond fossil resources, essential to the manufacture of many chemical goods other than fuels. Cobalt nanomaterials have been widely identified as a promising candidate for the anode (oxygen evolution) reaction in this process, but much work has focused on applied materials or

In this work, recent applications of XPS for the dispersion measurements of oxidic supports and metal catalysts were discussed. The most frequently used models, those of Kerkhof–Moulijn and Davis, were selected to give an overview of several applications in the study of catalysts, based on noble (Pd, Au, Ag, and Rh) and non-noble metals (Co, Ni). In the case of the dispersion of different promoters

Electron tomography (ET) has rapidly developed into a powerful technique to characterize the three-dimensional (3D) structure of complex materials, with nanometer resolution, for a wide range of applications including heterogeneous catalysis. In these 3D studies, scanning transmission electron microscopy (STEM) has been the most widely used imaging mode, due to both its incoherent nature, which avoids

The synthesis and characterization of an inexpensive porous MoxCy/SiO2 material is presented, which was obtained by mixing ammonium hexamolybdate, sucrose, and a mesoporous silica (SBA-15), with a subsequent heat treatment under inert atmosphere. This porous material presented a specific surface area of 170 m2/g. The catalytic behavior in CO2 hydrogenation was compared with that of Mo2C and α-MoC1−x