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Abstract: In the catalytic hydrogenation of α,β-unsaturated aldehydes and ketones, highly selective allylic alcohol formation can be achieved by application of Au0 nanocolloids dispersed in amide solvents. The polyvinylpyrrolidone protected Au0 nanoparticles prefer Con over Cion and act as chemoselective quasihomogeneous metal catalysts in the hydrogenation of trans-2-butenal (crotonaldehyde), 2-methyl-2-propenal (methacrolein), 4-methyl-3-penten-2-one (mesityl oxide) and 3-methyl-3-penten-2-one. An extensive solvent screening revealed the superiority of amides as media for both synthesis and application of the Au0 nanocolloids. In comparison with the widely used alcohol solvents, amides offer enhanced colloidal stability for the Au0 nanosol and increased hydrogenation chemoselectivity. Control over the Au0 cluster formation provided the opportunity to investigate the size-dependency of the catalytic performance and to determine the optimum gold cluster size for a maximization of the allylic alcohol yields. The most successful Au0 clusters, with a typical diameter of 7nm and synthesized in N,N-dimethylformamide, lead to a crotyl alcohol selectivity of 73% at 93% crotonaldehyde conversion and a 58% allylic alcohol yield in the hydrogenation of mesityl oxide at a molar substrate/Au catalyst ratio of 200. Analogous Pt0 and Ru0 sols are more active than the Au0 nanosols, but substantially less chemoselective for allylic alcohols. The Au0 nanocolloids can be recycled efficiently by ultrafiltration over custom-made, cross-linked polyimide membranes. In the recycling experiments the gold nanodispersion was well retained by the solvent-resistant ultrafiltration membranes and the performance of the colloidal gold catalyst was satisfactorily preserved in successive hydrogenation runs. [Copyright &y& Elsevier]

Abstract: The activation of propane both in the absence and presence of gas-phase O2 or CO2 over a CuO–CeO2/γ-Al2O3 catalyst is investigated in a TAP reactor between 623 and 873K. Two different types of oxygen species are involved dependent on the mixture introduced: (1) lattice oxygen from the surface and bulk of the catalyst and (2) weakly adsorbed oxygen species produced either from gas-phase O2 or CO2. Both types of oxygen species participate in the total oxidation of propane. If pulses of pure propane are admitted, lattice oxygen from CuO and CeO2 is consumed, reducing these oxides to a certain extent. Apart from surface lattice oxygen from CuO and CeO2, also bulk lattice oxygen is involved in the activation of propane, demonstrating the high O mobility within the lattice of these metal oxides. Lattice oxygen of alumina is not available for reaction with propane. Introduction of O2 reoxidizes the reduced sites on CuO and CeO2, as expected for a Mars–van Krevelen mechanism. Also CO2 can replenish O vacancies in the active phase by dissociative adsorption on alumina and ceria. The adsorption on alumina is followed by reverse spillover of reactive O species to the active phase. The second type of oxygen consists of weakly adsorbed oxygen species, produced either from O2 on both CuO and CeO2, or from CO2 on CeO2, and enhances strongly the catalytic activity. In the presence of both O2 and CO2 in the propane feed, the predominant reaction pathways will only involve the two types of active species produced from O2, and not from CO2. [ABSTRACT FROM AUTHOR]

Abstract: For photocatalytic thin film applications TiO2 is one of the most important materials. The most studied TiO2 crystal phase is anatase, though also rutile and brookite show good photoactivity. Usually anatase or a mixture of rutile and anatase is applied for powder or thin film catalysts. It has been claimed that amorphous films do not exhibit any or only a very low photocatalytic activity. We have deposited amorphous thin films by dc magnetron sputtering from sub-stoichiometric TiO2−x targets. The coatings are transparent and show a photocatalytic activity half of that of a thin layer of spin-coated reference photocatalyst powder. Annealing the thin films to yield anatase crystallization more than doubles their photocatalytic activity. At the same film thickness these thin films show the same activity as a commercially available photocatalytic coating. The dependence of the photocatalytic activity on deposition parameters like gas pressure and sputter power is discussed. A decrease in film density, as deduced from the refractive index and the microstructure, resulted in an increase in photocatalytic activity. Film thickness has a marked influence on the photocatalytic activity, showing a strong increase up to 300–400nm, followed by a much shallower slope. [Copyright &y& Elsevier]

Abstract: Pure and N-doped TiO2 nanoparticles are obtained by a combination of wet and thermal procedures, starting from TiCl3 and alkoxide precursors; the N-source is both inorganic (NH3) and organic (triethylamine). Samples are characterized for their bulk, surface, optical and magnetic properties. Ab initio calculations of the electronic properties of the doped samples are performed. Sample thin films are tested for their photocatalytic activity, under UV and simulated solar irradiation, with respect to air pollutants ethanol and acetaldehyde. Both the disappearance of the molecule itself and the complete mineralization (CO2) are followed during the reaction time. FTIR/ATR analyses are performed on samples withdrawn during the course of the reaction to identify reaction intermediates. In the case of acetaldehyde, photocatalytic tests are also performed under visible light (λ >400nm). The photoactivity sequences of the N-doped samples under the different irradiation sources are discussed with reference to their surface/bulk properties, light absorption features, nature and amount of paramagnetic species. [Copyright &y& Elsevier]

Abstract: Targets of 6 mm thickness were prepared from TiO2 powder with different amounts of Fe2O3 and Nd2O3 added. The targets were sintered in a vacuum furnace to obtain sub-stoichiometric rutile TiO2−x . For both added metal oxides, it was found that they were present as titanates forming a second phase. The sputtering behavior of these mixed-oxide targets was investigated. First, the dependence of the discharge voltage and the deposition speed on the argon pressure was measured. Second, the effect of the oxygen addition on the same two parameters was investigated. Both were compared with the dependencies measured for a pure TiO2−x target. All experiments were performed in constant power mode. The results show that Fe2O3 and Nd2O3 exhibit different effects on the sputtering behavior of TiO2−x targets. [Copyright &y& Elsevier]

Metal nanoparticle (NP) sintering is a major cause of catalyst deactivation, as NP growth reduces the surface area available for reaction. A promising route to halt sintering is to deposit a protective overcoat on the catalyst surface, followed by annealing to generate overlayer porosity for gas transport to the NPs. Yet, such a combined deposition-annealing approach lacks structural control over the cracked protection layer and the number of NP surface atoms available for reaction. Herein, we exploit the tailoring capabilities of atomic layer deposition (ALD) to deposit MgO overcoats on archetypal Pt NP catalysts with thicknesses ranging from sub-monolayers to nm-range thin films. Two different ALD processes are studied for the growth of MgO overcoats on Pt NPs anchored on a SiO 2 support, using Mg(EtCp) 2 and H 2 O, and Mg(TMHD) 2 and O 3 , respectively. Spectroscopic ellipsometry and X-ray photoelectron spectroscopy measurements reveal significant growth on both SiO 2 and Pt for the former process, while the latter exhibits a drastically lower growth per cycle with an initial chemical selectivity towards Pt. These differences in MgO growth characteristics have implications for the availability of uncoated Pt surface atoms at different stages of the ALD process, as probed by low energy ion scattering, and for the sintering behavior during O 2 annealing, as monitored in situ with grazing incidence small angle X-ray scattering ( in situ GISAXS). The Mg(TMHD) 2 -O 3 ALD process enables exquisite coverage control allowing a balance between physically blocking the Pt surface to prevent sintering and keeping Pt surface atoms free for reaction. This approach avoids the need for post-annealing, hence also safeguarding the structural integrity of the as-deposited overcoat.

The anti-inflammatory interleukin-1 receptor associated kinase-M (IRAK-M) is a negative regulator of MyD88/IRAK-4/IRAK-1 signaling. However, IRAK-M has also been reported to activate NF-κB through the MyD88/IRAK-4/IRAK-M myddosome in a MEKK-3 dependent manner. Here we provide support that IRAK-M uses three surfaces of its Death Domain (DD) to activate NF-κB downstream of MyD88/IRAK-4/IRAK-M. Surface 1, with central residue Trp74, binds to MyD88/IRAK-4. Surface 2, with central Lys60, associates with other IRAK-M DDs to form an IRAK-M homotetramer under the MyD88/IRAK-4 scaffold. Surface 3; with central residue Arg97 is located on the opposite side of Trp74 in the IRAK-M DD tetramer, lacks any interaction points with the MyD88/IRAK-4 complex. Although the IRAK-M DD residue Arg97 is not directly involved in the association with MyD88/IRAK-4, Arg97 was responsible for 50% of the NF-κB activation though the MyD88/IRAK-4/IRAK-M myddosome. Arg97 was also found to be pivotal for IRAK-M's interaction with IRAK-1, and important for IRAK-M's interaction with TRAF6. Residue Arg97 was responsible for 50% of the NF-κB generated by MyD88/IRAK-4/IRAK-M myddosome in IRAK-1/MEKK3 double knockout cells. By structural modeling we found that the IRAK-M tetramer surface around Arg97 has excellent properties that allow formation of an IRAK-M homo-octamer. This model explains why mutation of Arg97 results in an IRAK-M molecule with increased inhibitory properties: it still binds to myddosome, competing with myddosome IRAK-1 binding, while resulting in less NF-κB formation. The findings further identify the structure-function properties of IRAK-M, which is a potential therapeutic target in inflammatory disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor TR declared a past collaboration with the author WW., (Copyright © 2024 Gürkan, Poelman, Pereverzeva, Kruijswijk, de Vos, Groenen, Nollet, Wichapong, Lutgens, van der Poll, Du, Wiersinga, Nicolaes and van ‘t Veer.)

Vascular calcification (VC) is an important contributor and prognostic factor in the pathogenesis of cardiovascular diseases. VC is an active process mediated by the release of extracellular vesicles by vascular smooth muscle cells (VSMCs), and the enzyme neutral sphingomyelinase 2 (nSMase2 or SMPD3) plays a key role. Upon activation, the enzyme catalyzes the hydrolysis of sphingomyelin, thereby generating ceramide and phosphocholine. This conversion mediates the release of exosomes, a type of extracellular vesicles (EVs), which ultimately forms the nidus for VC. nSMase2 therefore represents a drug target, the inhibition of which is thought to prevent or halt VC progression. In search of novel druglike small molecule inhibitors of nSMase2, we have used virtual ligand screening to identify potential ligands. From an in-silico collection of 48,6844 small druglike molecules, we selected 996 compounds after application of an in-house multi-step procedure combining different filtering and docking procedures. Selected compounds were functionally tested in vitro; from this, we identified 52 individual hit molecules that inhibited nSMase2 activity by more than 20% at a concentration of 150 µM. Further analysis showed that five compounds presented with IC 50 s lower than 2 µM. Of these, compounds ID 5728450 and ID 4011505 decreased human primary VSMC EV release and calcification in vitro. The hit molecules identified here represent new classes of nSMase2 inhibitors that may be developed into lead molecules for the therapeutic or prophylactic treatment of VC.

MgAl 2 O 4 -supported Ni materials are highly active and cost-effective CO 2 conversion catalysts, yet their oxidation by CO 2 remains dubious. Herein, NiO/MgAl 2 O 4 , prepared via colloidal synthesis (10 wt % Ni) to limit size distribution, or wet impregnation (5, 10, 20, and 40 wt % Ni), and bare, i.e., unsupported, NiO are examined in H 2 reduction and CO 2 oxidation, using thermal conductivity detector-based measurements and in situ quick X-ray absorption spectroscopy, analyzed via multivariate curve resolution-alternating least-squares. Ni reoxidation does not occur for bare Ni but is observed solely on supported materials. Only samples with the smallest particle sizes get fully reoxidized. The Ni-MgAl 2 O 4 interface, exhibiting metal-support interactions, activates CO 2 and channels oxygen into the reduced lattice. Oxygen diffuses inward, away from the interface, oxidizing Ni entirely or partially, depending on the particle size in the applied oxidation time frame. This work provides evidence for Ni oxidation by CO 2 and explores the conditions of its occurrence and the importance of metal-support effects.

The spectro-kinetic characterization of complex catalytic materials, i.e. relating the observed reaction kinetics to spectroscopic descriptors of the catalyst state, presents a fundamental challenge with a potentially significant impact on various chemical technologies. We propose to reconcile the kinetic characteristics available from temporal analysis of products (TAP) pulse-response kinetic experiments with the spectroscopic data available from ambient pressure X-ray photoelectron spectroscopy (AP-XPS), using atomic layer deposition (ALD) to synthesize multicomponent model surfaces on 2D and 3D supports. The accumulated surface exposure to a key reactant (total number of collisions) is used as a common scale within which the results from the two techniques can be rigorously compared for microscopically-equivalent surfaces. This approach is illustrated by proof-of-principle TAP and AP-XPS experiments with PtIn/MgO/SiO 2 catalysts for alkane dehydrogenation at 800 K. Similarly to industrially-relevant Pt-based bimetallic catalysts on high-surface area supports, the initial period of coke accumulation on the surface resulted in gradually decreased conversion and increased selectivity towards propylene. We were able to monitor the process of coke deposition with both AP-XPS and TAP. The evolution of the C 1s photoelectron spectra is aligned on the common exposure scale with the evolution of the coke amounts deposited per Pt site during a multi-pulse TAP experiment. Moreover, TAP provided quantitative kinetic descriptors of propane consumption and product mean residence time within this common exposure scale. The challenges and opportunities presented by this novel tandem methodology are discussed in the context of catalysis research.

Signaling by Toll-Like Receptors and the Interleukin-1 Receptor (IL1-R) involves intracellular binding of MyD88, followed by assembly of IL1-R Associated Kinases (IRAKs) into the so-called Myddosome. Using NMR, Nechama et al. determined the structure of the IRAK-M death domain monomer (PDBid: 5UKE). With this structure, they performed a docking study to model the location of IRAK-M in the Myddosome. Based on this, they present a molecular basis for selectivity of IRAK-M towards IRAK1 over IRAK2 binding. When we attempted to use 5UKE as a homology modeling template, we noticed that our 5UKE-based models had structural issues, such as disallowed torsion angles and solvent exposed tryptophans. We therefore analyzed the NMR ensemble of 5UKE using structure validation tools and we compared 5UKE with homologous high-resolution X-ray structures. We identified several structural anomalies in 5UKE, including packing issues, frayed helices and improbable side chain conformations. We used Yasara to build a homology model, based on two high resolution death domain crystal structures, as an alternative model for the IRAK-M death domain (atomic coordinates, modeling details and validation are available at https://swift.cmbi.umcn.nl/gv/service/5uke/). Our model agrees better with known death domain structure information than 5UKE and also with the chemical shift data that was deposited for 5UKE., (Copyright © 2021. Published by Elsevier Inc.)

Urban accessibility and congestion indicators allow us to benchmark cities. If these indicators are also available at a fine resolution, we can compare different neighbourhoods within a city. We present a dataset of different accessibility indicators for all urban areas with more than 250 thousand people in the EU27, the UK, Switzerland and Norway. Each city is analysed by means of a population grid of 500 m by 500 m and represented by a wider area covering both the densely populated urban centre and the commuting zone. To capture congestion, we measure accessibility for each grid cell at different times of the day that correspond to different traffic conditions using the detailed network and congestion information provided by TomTom.

Supported nanoparticles are commonly applied in heterogeneous catalysis. The catalytic performance of these solid catalysts is, for a given support, dependent on the nanoparticle size, shape, and composition, thus necessitating synthesis techniques that allow for preparing these materials with fine control over those properties. Such control can be exploited to deconvolute their effects on the catalyst's performance, which is the basis for knowledge-driven catalyst design. In this regard, bottom-up synthesis procedures based on colloidal chemistry or atomic layer deposition (ALD) have proven successful in achieving the desired level of control for a variety of fundamental studies. This review aims to give an account of recent progress made in the two aforementioned synthesis techniques for the application of controlled catalytic materials in gas-phase catalysis. For each technique, the focus goes to mono- and bimetallic materials, as well as to recent efforts in enhancing their performance by embedding colloidal templates in porous oxide phases or by the deposition of oxide overlayers via ALD. As a recent extension to the latter, the concept of area-selective ALD for advanced atomic-scale catalyst design is discussed.

Atomic layer deposition (ALD) of noble metals is an attractive technology potentially applied in nanoelectronics and catalysis. Unlike the combustion-like mechanism shown by other noble metal ALD processes, the main palladium (Pd) ALD process using palladium(ii)hexafluoroacetylacetonate [Pd(hfac)2] as precursor is based on true reducing surface chemistry. In this work, a thorough investigation of plasma-enhanced Pd ALD is carried out by employing this precursor with different plasmas (H2*, NH3*, O2*) and plasma sequences (H2* + O2*, O2* + H2*) as co-reactants at varying temperatures, providing insights in the co-reactant and temperature dependence of the Pd growth per cycle (GPC). At all temperatures, films grown with only reducing co-reactants contain a large amount of carbon, while an additional O2* in the co-reactant sequence helps to obtain Pd films with much lower impurity concentrations. Remarkably, in situ XRD and SEM show an abrupt release of the carbon impurities during annealing at moderate temperatures in different atmospheres. In vacuo XPS measurements reveal the remaining species on the as-deposited surface after every exposure. Links are established between the particular surface termination prior to the precursor pulse and the observed differences in GPC, highlighting hydrogen as the key growth facilitator and carbon and oxygen as growth inhibitors. The increase in GPC with temperature for ALD sequences with H2* or NH3* prior to the precursor pulse is explained by an increase in the amount of hydrogen species that reside on the Pd surface which are available for reaction with the Pd(hfac)2 precursor.

Bimetallic nanocatalysts are key enablers of current chemical technologies, including car exhaust converters and fuel cells, and play a crucial role in industry to promote a wide range of chemical reactions. However, owing to significant characterization challenges, insights in the dynamic phenomena that shape and change the working state of the catalyst await further refinement. Herein, we discuss the atomic-scale processes leading to mono- and bimetallic nanoparticle formation and highlight the dynamics and kinetics of lifetime changes in bimetallic catalysts with showcase examples for Pt-based systems. We discuss how in situ and operando X-ray spectroscopy, scattering, and diffraction can be used as a complementary toolbox to interrogate the working principles of today's and tomorrow's bimetallic nanocatalysts., (© 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

The horizon of drug discovery is currently expanding to target and modulate protein-protein interactions (PPIs) in globular proteins and intrinsically disordered proteins that are involved in various diseases. To either interrupt or stabilize PPIs, the 3D structure of target protein-protein (or protein-peptide) complexes can be exploited to rationally design PPI modulators (inhibitors or stabilizers) through structure-based molecular design. In this review, we present an overview of experimental and computational methods that can be used to determine 3D structures of protein-protein complexes. Several approaches including rational and in silico methods that can be applied to design peptides, peptidomimetics and small compounds by utilization of determined 3D protein-protein/peptide complexes are summarized and illustrated.

Aims: The E3-ligase CBL-B (Casitas B-cell lymphoma-B) is an important negative regulator of T cell activation that is also expressed in macrophages. T cells and macrophages mediate atherosclerosis, but their regulation in this disease remains largely unknown; thus, we studied the function of CBL-B in atherogenesis., Methods and Results: The expression of CBL-B in human atherosclerotic plaques was lower in advanced lesions compared with initial lesions and correlated inversely with necrotic core area. Twenty weeks old Cblb-/-Apoe-/- mice showed a significant increase in plaque area in the aortic arch, where initial plaques were present. In the aortic root, a site containing advanced plaques, lesion area rose by 40%, accompanied by a dramatic change in plaque phenotype. Plaques contained fewer macrophages due to increased apoptosis, larger necrotic cores, and more CD8+ T cells. Cblb-/-Apoe-/- macrophages exhibited enhanced migration and increased cytokine production and lipid uptake. Casitas B-cell lymphoma-B deficiency increased CD8+ T cell numbers, which were protected against apoptosis and regulatory T cell-mediated suppression. IFNγ and granzyme B production was enhanced in Cblb-/-Apoe-/- CD8+ T cells, which provoked macrophage killing. Depletion of CD8+ T cells in Cblb-/-Apoe-/- bone marrow chimeras rescued the phenotype, indicating that CBL-B controls atherosclerosis mainly through its function in CD8+ T cells., Conclusion: Casitas B-cell lymphoma-B expression in human plaques decreases during the progression of atherosclerosis. As an important regulator of immune responses in experimental atherosclerosis, CBL-B hampers macrophage recruitment and activation during initial atherosclerosis and limits CD8+ T cell activation and CD8+ T cell-mediated macrophage death in advanced atherosclerosis, thereby preventing the progression towards high-risk plaques.

Alloyed metal nanocatalysts are of environmental and economic importance in a plethora of chemical technologies. During the catalyst lifetime, supported alloy nanoparticles undergo dynamic changes which are well-recognized but still poorly understood. High-temperature O 2 -H 2 redox cycling was applied to mimic the lifetime changes in model Pt 13 In 9 nanocatalysts, while monitoring the induced changes by in situ quick X-ray absorption spectroscopy with one-second resolution. The different reaction steps involved in repeated Pt 13 In 9 segregation-alloying are identified and kinetically characterized at the single-cycle level. Over longer time scales, sintering phenomena are substantiated and the intraparticle structure is revealed throughout the catalyst lifetime. The in situ time-resolved observation of the dynamic habits of alloyed nanoparticles and their kinetic description can impact catalysis and other fields involving (bi)metallic nanoalloys., (© 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

Combining chemical looping with a traditional fuel conversion process yields a promising technology for low-CO₂-emission energy production. Bridged by the cyclic transformation of a looping material (CO₂ carrier or oxygen carrier), a chemical looping process is divided into two spatially or temporally separated half-cycles. Firstly, the oxygen carrier material is reduced by fuel, producing power or chemicals. Then, the material is regenerated by an oxidizer. In chemical looping combustion, a separation-ready CO₂ stream is produced, which significantly improves the CO₂ capture efficiency. In chemical looping reforming, CO₂ can be used as an oxidizer, resulting in a novel approach for efficient CO₂ utilization through reduction to CO. Recently, the novel process of catalyst-assisted chemical looping was proposed, aiming at maximized CO₂ utilization via the achievement of deep reduction of the oxygen carrier in the first half-cycle. It makes use of a bifunctional looping material that combines both catalytic function for efficient fuel conversion and oxygen storage function for redox cycling. For all of these chemical looping technologies, the choice of looping materials is crucial for their industrial application. Therefore, current research is focused on the development of a suitable looping material, which is required to have high redox activity and stability, and good economic and environmental performance. In this review, a series of commonly used metal oxide-based materials are firstly compared as looping material from an industrial-application perspective. The recent advances in the enhancement of the activity and stability of looping materials are discussed. The focus then proceeds to new findings in the development of the bifunctional looping materials employed in the emerging catalyst-assisted chemical looping technology. Among these, the design of core-shell structured Ni-Fe bifunctional nanomaterials shows great potential for catalyst-assisted chemical looping.

Onset of cardiovascular complications as a consequence of atherosclerosis exhibits a circadian incidence with a peak in the morning hours. Although development of atherosclerosis extends for long periods of time through arterial leukocyte recruitment, we hypothesized that discrete diurnal invasion of the arterial wall could sustain atherogenic growth. Here, we show that myeloid cell recruitment to atherosclerotic lesions oscillates with a peak during the transition from the activity to the resting phase. This diurnal phenotype is regulated by rhythmic release of myeloid cell-derived CCL2, and blockade of its signaling abolished oscillatory leukocyte adhesion. In contrast, we show that myeloid cell adhesion to microvascular beds peaks during the early activity phase. Consequently, timed pharmacological CCR2 neutralization during the activity phase caused inhibition of atherosclerosis without disturbing microvascular recruitment. These findings demonstrate that chronic inflammation of large vessels feeds on rhythmic myeloid cell recruitment, and lay the foundation for chrono-pharmacology-based therapy., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The role of iron in view of its further utilization in chemical processes is presented, based on current knowledge of its properties. The addition of iron to a catalyst provides redox functionality, enhancing its resistance to carbon deposition. FeO x species can be formed in the presence of an oxidizing agent, such as CO₂, H₂O or O₂, during reaction, which can further react via a redox mechanism with the carbon deposits. This can be exploited in the synthesis of active and stable catalysts for several processes, such as syngas and chemicals production, catalytic oxidation in exhaust converters, etc. Iron is considered an important promoter or co-catalyst, due to its high availability and low toxicity that can enhance the overall catalytic performance. However, its operation is more subtle and diverse than first sight reveals. Hence, iron and its oxides start to become a hot topic for more scientists and their findings are most promising. The scope of this article is to provide a review on iron/iron-oxide containing catalytic systems, including experimental and theoretical evidence, highlighting their properties mainly in view of syngas production, chemical looping, methane decomposition for carbon nanotubes production and propane dehydrogenation, over the last decade. The main focus goes to Fe-containing nano-alloys and specifically to the Fe⁻Ni nano-alloy, which is a very versatile material.

V 2 O 5 with a layered van der Waals (vdW) structure has been widely studied because of the material's potential in applications such as battery electrodes. In this work, microelectronic devices were fabricated to study the electrical and optical properties of mechanically exfoliated multilayered V 2 O 5 flakes. Raman spectroscopy was used to determine the crystal structure axes of the nanoflakes and revealed that the intensities of the Raman modes depend strongly on the relative orientation between the crystal axes and the polarization directions of incident/scattered light. Angular dependence of four-probe resistance measured in the van der Pauw (vdP) configuration revealed an in-plane anisotropic resistance ratio of ∼100 between the a and b crystal axes, the largest in-plane transport anisotropy effect experimentally reported for two-dimensional (2D) materials to date. This very large resistance anisotropic ratio is explained by the nonuniform current flow in the vdP measurement and an intrinsic mobility anisotropy ratio of 10 between the a and b crystal axes. Room-temperature electron Hall mobility up to 7 cm 2 /(V s) along the high-mobility direction was obtained. This work demonstrates V 2 O 5 as a layered 2D vdW oxide material with strongly anisotropic optical and electronic properties for novel applications.

Efficient CO 2 transformation from a waste product to a carbon source for chemicals and fuels will require reaction conditions that effect its reduction. We developed a "super-dry" CH 4 reforming reaction for enhanced CO production from CH 4 and CO 2 We used Ni/MgAl 2 O 4 as a CH 4 -reforming catalyst, Fe 2 O 3 /MgAl 2 O 4 as a solid oxygen carrier, and CaO/Al 2 O 3 as a CO 2 sorbent. The isothermal coupling of these three different processes resulted in higher CO production as compared with that of conventional dry reforming, by avoiding back reactions with water. The reduction of iron oxide was intensified through CH 4 conversion to syngas over Ni and CO 2 extraction and storage as CaCO 3 CO 2 is then used for iron reoxidation and CO production, exploiting equilibrium shifts effected with inert gas sweeping (Le Chatelier's principle). Super-dry reforming uses up to three CO 2 molecules per CH 4 and offers a high CO space-time yield of 7.5 millimole CO per second per kilogram of iron at 1023 kelvin., (Copyright © 2016, American Association for the Advancement of Science.)

The enzyme 15-lipoxygenase-1 (15-LOX-1) plays a dual role in diseases with an inflammatory component. On one hand 15-LOX-1 plays a role in pro-inflammatory gene expression and on the other hand it has been shown to be involved in central nervous system (CNS) disorders by its ability to mediate oxidative stress and damage of mitochondrial membranes under hypoxic conditions. In order to further explore applications in the CNS, novel 15-LOX-1 inhibitors with favorable physicochemical properties need to be developed. Here, we present Substitution Oriented Screening (SOS) in combination with Multi Component Chemistry (MCR) as an effective strategy to identify a diversely substituted small heterocyclic inhibitors for 15-LOX-1, denoted ThioLox, with physicochemical properties superior to previously identified inhibitors. Ex vivo biological evaluation in precision-cut lung slices (PCLS) showed inhibition of pro-inflammatory gene expression and in vitro studies on neuronal HT-22 cells showed a strong protection against glutamate toxicity for this 15-LOX-1 inhibitor. This provides a novel approach to identify novel small with favorable physicochemical properties for exploring 15-LOX-1 as a drug target in inflammatory diseases and neurodegeneration., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Since their early discovery, bimetallic nanoparticles have revolutionized various fields, including nanomagnetism and optics as well as heterogeneous catalysis. Knowledge buildup in the past decades has witnessed that the nanoparticle size and composition strongly impact the nanoparticle's properties and performance. Yet, conventional synthesis strategies lack proper control over the nanoparticle morphology and composition. Recently, atomically precise synthesis of bimetallic nanoparticles has been achieved by atomic layer deposition (ALD), alleviating particle size and compositional nonuniformities. However, this bimetal ALD strategy applies to noble metals only, a small niche within the extensive class of bimetallic alloys. We report an ALD-based approach for the tailored synthesis of bimetallic nanoparticles containing both noble and non-noble metals, here exemplified for Pt-In. First, a Pt/In2O3 bilayer is deposited by ALD, yielding precisely defined Pt-In nanoparticles after high-temperature H2 reduction. The nanoparticles' In content can be accurately controlled over the whole compositional range, and the particle size can be tuned from micrometers down to the nanometer scale. The size and compositional flexibility provided by this ALD-approach will trigger the fabrication of fully tailored bimetallic nanomaterials, including superior nanocatalysts.

Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms - such as hydrogen-spillover, surface migration - have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 °C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga(3+) cations in the support. Only in the presence of Pt, partial reduction of Ga(3+) into Ga(δ+) is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga(3+) is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Ga(δ+)Ox migrates towards Pt clusters, where Ga(δ+) is only fully reduced to Ga(0) on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles.

Mesoporous carbons were synthesized via both soft and hard template methods and compared to a commercial powder activated carbon (PAC) for the adsorption ability of bisphenol-A (BPA) from an aqueous solution. The commercial PAC had a BET-surface of 1027 m²/g with fine pores of 3 nm and less. The hard templated carbon (CMK-3) material had an even higher BET-surface of 1420 m²/g with an average pore size of 4 nm. The soft templated carbon (SMC) reached a BET-surface of 476 m²/g and a pore size of 7 nm. The maximum observed adsorption capacity (q max ) of CMK-3 was the highest with 474 mg/g, compared to 290 mg/g for PAC and 154 mg/g for SMC. The difference in adsorption capacities was attributed to the specific surface area and hydrophobicity of the adsorbent. The microporous PAC showed the slowest adsorption, while the ordered mesopores of SMC and CMK-3 enhanced the BPA diffusion into the adsorbent. This difference in adsorption kinetics is caused by the increase in pore diameter. However, CMK-3 with an open geometry consisting of interlinked nanorods allows for even faster intraparticle diffusion.

Complementary to conventional X-ray absorption near edge structure (XANES) and Fourier transformed (FT) extended X-ray absorption fine structure (EXAFS) analysis, the systematic application of wavelet transformed (WT) XAS is shown to disclose the physicochemical mechanisms governing Pt-In catalyst formation. The simultaneous k- and R-space resolution of the WT XAS signal allows for the efficient allocation of the elemental nature to each R-space peak. Because of its elemental discrimination capacity, the technique delivers structural models which can subsequently serve as an input for quantitative FT EXAFS modeling. The advantages and limitations of applying WT XAS are demonstrated (1) before and (2) after calcination to 650 °C of a Pt(acac)2 impregnated Mg(In)(Al)Ox support and (3) after subsequent H2 reduction to 650 °C. Combined XANES, FT, and WT XAS analysis shows that the acac ligands of the Pt precursor decompose during calcination, leading to atomically dispersed Pt(4+) cations on the Mg(In)(Al)Ox support. H2 reduction treatment eventually results in the formation of 1.5 nm Pt-In alloyed nanoparticles. Widespread use and systematic application of wavelet-based XAS can potentially reveal in greater detail the intricate mechanisms involved in catalysis, chemistry, and related fields.

Nanoscale Fe : CeO2-x oxygen storage material for the process of chemical looping has been investigated by advanced transmission electron microscopy and electron energy-loss spectroscopy before and after a model looping procedure, consisting of redox cycles at heightened temperature. Separately, the activity of the nanomaterial has been tested in a toluene total oxidation reaction. The results show that the material consists of ceria nanoparticles, doped with single Fe atoms and small FeOx clusters. The iron ion is partially present as Fe(3+) in a solid solution within the ceria lattice. Furthermore, enrichment of reduced Fe(2+) species is observed in nanovoids present in the ceria nanoparticles, as well as at the ceria surface. After chemical looping, agglomeration occurs and reduced nanoclusters appear at ceria grain boundaries formed by sintering. These clusters originate from surface Fe(2+) aggregation, and from bulk Fe(3+), which "leaks out" in reduced state after cycling to a slightly more agglomerated form. The activity of Fe : CeO2 during the toluene total oxidation part of the chemical looping cycle is ensured by the dopant Fe in the Fe1-xCexO2 solid solution, and by surface Fe species. These measurements on a model Fe : CeO2-x oxygen storage material give a unique insight into the behavior of dopants within a nanosized ceria host, and allow to interpret a plethora of (doped) cerium oxide-based reactions.