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Within this perspective article, we intend to summarise definitions and terms that are often used in the context of open science and data-driven R&D and we discuss upcoming European regulations concerning data, data sharing and handling. With this background in hand, we take a closer look at the potential connections and permeable interfaces of open science and digital economy, in which data and resulting immaterial goods can become vital pieces as tradeable items. We believe that both science and the digital economy can profit from a seamless transition and foresee that the scientific outcomes of publicly funded research can be better exploited. To close the gap between open science and the digital economy, and to serve for a balancing of the interests of data producers, data consumers, and an economy around services and the public, we introduce the concept of generic research data management plans (RDMs), which have in part been developed through a community effort and which have been evaluated by academic and industry members of the NFDI4Cat consortium. We are of the opinion that in data-driven research, RDMs do need to become a vital element in publicly funded projects.
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The ethylene epoxidation is a challenging catalytic process, and development of active and selective catalyst requires profound understanding of its chemical behaviour under reaction conditions. The systematic study on intermetallic compounds in the Ca-Ag system under ethylene epoxidation conditions clearly shows that the character of the oxidation processes on the surface originates from the atomic interactions in the pristine compound. The Ag-rich compounds Ca2Ag7 and CaAg2 undergo oxidation towards fcc Ag and a complex Ca-based support, whereas equiatomic CaAg and the Ca-rich compounds Ca5Ag3 and Ca3Ag in bulk remain stable under harsh ethylene epoxidation conditions. For the latter presence of water vapour in the gas stream leads to noticeable corrosion. Combining the experimental results with the chemical bonding analysis and first-principles calculations, the relationships among the chemical nature of the compounds, their reactivity and catalytic performance towards epoxidation of ethylene are investigated.
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The direct conversion of syngas to ethanol, typically using promoted Rh catalysts, is a cornerstone reaction in CO2 utilization and hydrogen storage technologies. A rational catalyst development requires a detailed structural understanding of the activated catalyst and the role of promoters in driving chemoselectivity. Herein, we report a comprehensive atomic-scale study of metal-promoter interactions in silica-supported Rh, Rh-Mn, and Rh-Mn-Fe catalysts by aberration-corrected (AC) TEM. While the catalytic reaction leads to the formation of a Rh carbide phase in the Rh-Mn/SiO2 catalyst, the addition of Fe results in the formation of bimetallic Rh-Fe alloys, which further improves the selectivity and prevents the carbide formation. In all promoted catalysts, Mn is present as an oxide decorating the metal particles. Based on the atomic insight obtained, structural and electronic modifications induced by promoters are revealed and a basis for refined theoretical models is provided.
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The mutual interaction between Rh nanoparticles and manganese/iron oxide promoters in silica-supported Rh catalysts for the hydrogenation of CO to higher alcohols was analyzed by applying a combination of integral techniques including temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and Fourier transform infrared (FTIR) spectroscopy with local analysis by using high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) in combination with energy dispersive X-ray spectroscopy (EDX). The promoted catalysts show reduced CO adsorption capacity as evidenced through FTIR spectroscopy, which is attributed to a perforated core-shell structure of the Rh nano-particles in accordance with the microstructural analysis from electron microscopy. Iron and manganese occur in low formal oxidation states between 2+ and zero in the reduced catalysts as shown by using TPR and XAS. Infrared spectroscopy measured in diffuse reflectance at reaction temperature and pressure indicates that partial coverage of the Rh particles is maintained at reaction temperature under operation and that the remaining accessible metal adsorption sites might be catalytically less relevant because the hydrogenation of adsorbed carbonyl species at 523 K and 30 bar hydrogen essentially failed. It is concluded that Rh0 is poisoned due to the adsorption of CO under the reaction conditions of CO hydrogenation. The active sites are associated either with a (Mn,Fe)Ox (x < 0.25) phase or species at the interface between Rh and its co-catalyst (Mn,Fe)Ox.
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The chemical behavior of CaAg as catalyst for ethylene epoxidation was studied using a combination of experimental (X-ray powder diffraction, scanning electron microscopy, thermal analysis and infrared spectroscopy), and quantum chemical techniques as well as real-space chemical bonding analysis. Under oxidative ethylene epoxidation conditions, the CaAg (010) surface possesses an outstanding stability during long-term experiments. It is caused by the formation of an ordered, stable and dense CaO passivation layer with a small amount of embedded Ag atoms. On this way, the (010) surface constitutes a kinetic barrier for further incorporation of oxygen into the subsurface region and thereby prevents further oxidative decomposition of CaAg. The calculated adsorption energies of the reaction species show strong adsorption of the reaction products that may explain the observed low conversion of ethylene toward ethylene oxide using CaAg as catalyst.
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Early-late intermetallic phases have garnered increased attention recently for their catalytic properties. To achieve the high surface areas needed for industrially relevant applications, these phases must be synthesized as nanoparticles in a scalable fashion. Herein, Pt3Y-targeted as a prototypical example of an early-late intermetallic-has been synthesized as nanoparticles approximately 5-20 nm in diameter via a solution process and characterized by XRD, TEM, EDS, and XPS. The key development is the use of a molten borohydride (MEt3BH, M = Na, K) as both the reducing agent and reaction medium. Readily available halide precursors of the two metals are used. Accordingly, no organic ligands are necessary, as the resulting halide salt byproduct prevents sintering, which further permits dispersion of the nanoscale intermetallic onto a support. The versatility of this approach was validated by the synthesis of other intermetallic phases such as Pt3Sc, Pt3Lu, Pt2Na, and Au2Y.
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The nickel-catalyzed direct carboxylation of alkenes with the cheap and abundantly available C1 building block carbon dioxide (CO2 ) in the presence of a base has been achieved. The one-pot reaction allows for the direct and selective synthesis of a wide range of α,ß-unsaturated carboxylates (TON>100, TOF up to 6â h(-1) , TON=turnover number, TOF=turnover frequency). Thus, it is possible, in one step, to synthesize sodium acrylate from ethylene, CO2 , and a sodium salt. Acrylates are industrially important products, the synthesis of which has hitherto required multiple steps.
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For more than three decades the catalytic synthesis of acrylates from the cheap and abundantly available C(1) building block carbon dioxide and alkenes has been an unsolved problem in catalysis research, both in academia and industry. Herein, we describe a homogeneous catalyst based on nickel that permits the catalytic synthesis of the industrially highly relevant acrylate sodium acrylate from CO(2), ethylene, and a base, as demonstrated, at this stage, by a turnover number of greater than 10 with respect to the metal.
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The design of heterogeneous catalysts is challenged by the complexity of materials and processes that govern reactivity and by the fact that the number of good catalysts is very small in comparison to the number of possible materials. Here, we show how the subgroup-discovery (SGD) artificial-intelligence approach can be applied to an experimental plus theoretical data set to identify constraints on key physicochemical parameters, the so-called SG rules, which exclusively describe materials and reaction conditions with outstanding catalytic performance. By using high-throughput experimentation, 120 SiO2-supported catalysts containing ruthenium, tungsten, and phosphorus were synthesized and tested in the catalytic oxidation of propylene. As candidate descriptive parameters, the temperature and 10 parameters related to the composition and chemical nature of the catalyst materials, derived from calculated free-atom properties, were offered. The temperature, the phosphorus content, and the composition-weighted electronegativity are identified as key parameters describing high yields toward the value-added oxygenate products acrolein and acrylic acid. The SG rules not only reflect the underlying processes particularly associated with high performance but also guide the design of more complex catalysts containing up to five elements in their composition.
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Complex multi-element lead structures of mixed metal oxides that may be identified as hits during high throughput experimentation (HTE) campaigns, can be deconvoluted retrospectively on the basis of simple binary and ternary oxides as illustrated in the current example of a hit found in an ammoxidation reaction. On the basis of the performance of the simple binary and ternary mixed metal oxides structure property relationships can be established, that give insight into the roles of the different components of the complex mixed metal oxides and may also help in establishing a reaction mechanism and converting the hit into a development candidate.
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Técnicas Químicas Combinatorias , Metales/química , Óxidos/química , Relación Estructura-Actividad Cuantitativa , Catálisis , Gases/química , Estructura Molecular , Oxidación-ReducciónRESUMEN
We report the first catalyst based on palladium for the reaction of CO2, alkene and a base to form sodium acrylate and derivatives. A mechanism similar to a previously reported Ni(0)-catalyst is proposed based on stoichiometric in situ NMR experiments, isolated intermediates and a parent palladalactone. Our palladium catalyst was applied to the coupling of CO2 with conjugated alkenes.
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A continuous process for the synthesis of mesoporous silicates such as MCM-41 at room temperature has been achieved by employing a tubular reactor in which tetraethoxysilane was used as the silicate source (see schematic representation below). The formation of the hexagonal mesophase, which was monitored by using in situ XRD at different points of the tube, was completed in three minutes after mixing of the reactants. The product was stable to calcination, and N2 -sorption measurements confirmed the high surface area and narrow pore-size distribution.
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Renewable feedstocks have been in the spotlight of intensive research activities over the past 10 years. Glycerol is one of the feedstock molecules which has been the target of numerous research efforts, for a number of reasons. First of all glycerol is currently readily available due to the fact that it is a couple product of the first generation biodiesel production. Secondly glycerol can be taken as a representative model substrate to explore the options of selective conversion of sugar alcohols to products of value. In our paper we discuss potential routes for the valorisation of glycerol which lead to intermediates already established within the petrochemical value chain and illustrate what impact high throughput experimentation may have as a success factor on research and development for this field. As illustrative examples we have chosen the oxidative transformation of glycerol to acrolein and acrylic acid and the carbonylation of glycerol to C4-acids.
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Acroleína/síntesis química , Acrilatos/síntesis química , Glicerol/química , Ensayos Analíticos de Alto Rendimiento , Alcoholes del Azúcar/síntesis química , Acroleína/química , Acrilatos/química , Estructura Molecular , Oxidación-Reducción , Alcoholes del Azúcar/químicaRESUMEN
Co and Mn polysiloxanes are unique catalyst/initiator systems for the liquid phase oxidation of o-xylene showing higher activity than Co naphthenates, which is related to the weak interaction of the polar products with the hydrophobic surface as well as the absence of hydroxyl groups and surrounding oxygenates limiting radical quenching.