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Strong metal–support interaction (SMSI) is a pivotal strategy in thermal catalysis; however, its application in photocatalysis leaves ample area for further development. A method inducing SMSI between earth-abundant metals, such as copper and TiO2, at room temperature, and thus hindering the agglomeration of copper species remains rarely reported. In this work, we achieved SMSI construction of TiO2 overlayers on Cu nanoparticles via a straightforward soft-chemistry method. SMSI coverage is stable even after high-temperature treatment in the air (500 °C), as demonstrated by chemical mapping and surface analysis. The method is more accurate than thermal reduction since it produces a metastable, highly active anatase phase. Interestingly, the TiO2 overlayer induces the formation of four-coordinated copper(II) species surrounded by oxygen atoms, resulting in coexisting CuO2 planes, which were monitored through high-resolution transmission electron microscopy and electron paramagnetic resonance spectroscopy. The stronger interfacial interaction by forming Ti–O–Cu bonding promotes charge carrier separation, producing twice as much H2 than the low interfacial interaction within a conventional photoactive system wherein copper was decorated onto TiO2. Our approach offers a rational design for SMSI materials in photocatalysis, which is extendable to other catalytic reactions. [ABSTRACT FROM AUTHOR]

The design of an "H"‐shaped reactor has been studied to satisfy the possibility of using a triphasic medium to transform d‐glucose into 5‐hydroxymethylfurfural (HMF) by a hybrid catalytic process using an immobilized glucose isomerase, allowing the isomerization of D‐glucose to d‐fructose, and a heterogeneous chemical catalyst to catalyze the dehydration of d‐fructose to HMF. The various parameters influencing the transport of d‐fructose within the reactor were studied, namely the difference in pH between the two aqueous phases, the agitation and the quantity of 3,4‐DCPBA/Aliquat336® used to extract and transport continuously the d‐fructose. The pH discrepancy, which must be between 5.0 and 5.5, turns out to be the real driving force behind the extraction of D‐fructose. The D‐Fru/3,4‐DCPBA molar ratio of 1/0.25 allowed the transport of more than 80 % of the D‐fructose initially present and shows that the same molecule of 3,4‐DCPBA is involved at least twice in the transport of D‐fructose and that the 3,4‐DCPBA/Aliquat336® couple performs a turnover within the organic phase. Finally, a HMF production yield of 30.9 % and an isomerization yield of 79.1 % were obtained, illustrating the shift in the isomerization equilibrium made possible by a D‐fructose extraction yield of 96.8 %. [ABSTRACT FROM AUTHOR]

With the development of a strong bioeconomy sector related to the creation of next-generation biorefineries, heterogeneous catalysis is receiving renewed attention. Indeed, catalysis is at the core of biorefinery design, and many new catalysts and catalytic processes are being developed. On the one hand, they are based on knowledge acquired during the last century to efficiently upgrade fossil resources. On the other hand, they take advantage of the opportunity of having new substrates on which novel conversion technologies, derived from recent fundamental advances and new concepts developed in the field of heterogeneous catalysis, can be tested and applied. In this context, there is a global trend for establishing new courses throughout the world to train students and professionals in the bioeconomy/biorefinery sector. Such courses encompass many different fields in a multidisciplinary approach, including agronomy, logistics, life cycle assessment, biotechnologies, process design, economics, and, obviously, chemistry. For the last of these, a specific important role is given to catalysis, and more especially to heterogeneous catalysis. Such courses need to explain the basics of each scientific field involved before giving concrete examples of research/development. Among them, the aforementioned heterogeneous catalysis is an especially complex scientific field in which surface science, spectroscopy, thermodynamics, and other disciplines are intimately interwoven. While many references presenting specific aspects of catalysis can be found, concise documents encompassing all of the angles of this very rich field--including its most recent developments and prospects, aimed at a readership already trained in chemistry--are scarce. This paper gives a global and simple "heterogeneous catalysis tour" to explain in a concise way what heterogeneous catalysis is without going into too much detail. The students who would like to know more about some specific aspects will find useful authoritative references in the text, making this paper a good introduction to all aspects of heterogeneous catalysis.

Supported gold nanoparticles have proven to be highly effective catalysts for the base-free oxidation of furfural, a compound derived from biomass. Their small size enables a high surface-area-to-volume ratio, providing abundant active sites for the reaction to take place. These gold nanoparticles serve as catalysts by providing surfaces for furfural molecules to adsorb onto and facilitating electron transfer between the substrate and the oxidizing agent. The role of the support in this reaction has been widely studied, and gold–support interactions have been found to be beneficial. However, the exact mechanism of furfural oxidation under base-free conditions remains an active area of research and is not yet fully understood. In this review, we delve into the essential factors that influence the selectivity of furfural oxidation. We present an optimization process that highlights the significant role of machine learning in identifying the best catalyst for this reaction. The principal objective of this study is to provide a comprehensive review of research conducted over the past five years concerning the catalytic oxidation of furfural under base-free conditions. By conducting tree decision making on experimental data from recent articles, a total of 93 gold-based catalysts are compared. The relative variable importance chart analysis reveals that the support preparation method and the pH of the solution are the most crucial factors determining the yield of furoic acid in this oxidation process. [ABSTRACT FROM AUTHOR]

Catalysis, irrespective of its form can be considered as one of the most important pillars of today’s chemical industry. The development of new catalysts with improved performances is therefore a highly strategic issue. However, the a priori theoretical design of the best catalyst for a desired reaction is not yet possible and a time- and money-consuming experimental phase is still needed to develop a new catalyst for a given reaction. The REALCAT platform described in this paper consists in a complete, unique, integrated and top-level high-throughput technologies workflow that allows a significant acceleration of this kind of research. This is illustrated by some preliminary results of optimization of the operating conditions of glycerol dehydration to acrolein over an heteropolyacid-based supported catalyst. It is shown that using REALCAT high-throughput tools a more than 10-fold acceleration of the operating conditions optimization process is obtained.

This study explores the performances of nickel‐based materials for the dry reforming of methane (DRM), an important process for hydrogen and syngas productions. Ni nanoparticles are issued from porous phyllosilicate phase exolution under reducing conditions (in situ or ex situ). Phyllosilicate precursors were obtained by deposition/precipitation with urea onto SBA‐15 porous silica, with metal loading up to 40 wt.%. Reaction was performed at 600–700 °C. The successful formation and stabilization of highly dispersed nanoparticles (2–6 nm) is revealed, even for highly loaded formulations (20 wt.% and 40 wt.%). In DRM‐700 (CH4/CO2=1, 20 % CH4, 480,000 mL gcat−1 h−1) the formulation at 20 wt.% metal loading (Ni_20 %) activated during reaction affords 50 % and 65 % of CH4 and CO2 conversions respectively at 700 °C. Ni_20 % is showing excellent resistance toward sintering after DRM stability test of 80 h. Characterizations made for spent catalyst show high resistance toward sintering and limited carbon formation. [ABSTRACT FROM AUTHOR]

Castor and its derived oil, the so-called ‘‘castor oil’’, are known from the ancient times, when the oil was used for cosmectics, or as a laxative, or as a fuel in lamps. Nowadays, castor oil has a completely renewed interest, not for its direct applications, but thanks to various possibilities in downstream processing, which involves chemical modifications & reactions. Indeed, castor oil has this specifiticy of a remarkable uniformity, with about 90% of the fatty acid chains of the triglyceride composed of ricinoleic acid, a natural fatty acid behaving a hydroxyle group, which is a unique feature in vegetal oils. Then, it is possible to envision reactions either on the ester group, on the double bond or even on the hydroxyle moety to yield a variety of chemicals. In this paper, after a short description of the castor plant, we give statistics on the production of castor grains and an overview on the oil extraction process. Then, we report the market prices before listing the main properties of castor oil. These latter are quite specific and explain the large variety of possible direct applications. At last, the possible chemical transformations are listed, before giving two practical cases, as actual industrialisation success stories.

The development of the future French and European bioeconomies will involve developing new green chemical processes in which catalytic transformations are key. The VAALBIO team (valorization of alkanes and biomass) of the UCCS laboratory (Unité de Catalyse et Chimie du Solide) are working on various catalytic processes, either developing new catalysts and/or designing the whole catalytic processes. Our research is focused on both the fundamental and applied aspects of the processes. Through this review paper, we demonstrate the main topics developed by our team focusing mostly on oxygen- and hydrogen-related processes as well as on green hydrogen production and hybrid catalysis. The social impacts of the bioeconomy are also discussed applying the concept of the institutional compass. [ABSTRACT FROM AUTHOR]

Oxidative deamination is part of the metabolic pathways of amino acid oxidase and glutamate dehydrogenase enzymes, and enables obtaining α‐keto acid from amino compound with ammonia as a by‐product. This work presents the utilization of Pt‐based catalyst composed of small platinum nanoparticles supported on industrial silica support (Pt/SiO2). This nanozyme was tested in the oxidative deamination reaction of two amino compounds: 5‐hydroxymethylfurfurylamine (HMFA) to 5‐hydroxymethylfurfural (HMF) and glutamic acid (GA) to α‐ketoglutaric acid (KGA). This paper outlines the use of Pt nanozymes with deaminase‐like activity. We showed the ability of this nanozymes to be selective and active in liquid phase oxidative deamination of HMFA and glutamic acid in a 6 to 9 pH range at 60 °C under atmospheric pressure. Pt/SiO2 nanozyme actually plays as a deaminase mimic with high HMFA conversion (60%) and cumulative yield to the corresponding desaminated keto compounds (67%). [ABSTRACT FROM AUTHOR]

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Core–shell SiO2@Au@TiO2 materials have shown excellent catalytic performances in the base-free oxidation of furfural (FF) to furoic acid (FA). The enhanced catalytic behaviour with respect to that observed over supported SiO2@TiO2@Au catalysts suggests a key role of the TiO2 shell, which could prevent Au deactivation by irreversible FA adsorption, improve metal–oxide interaction and presumably, give rise to the formation of new active sites located at the perimeter of the Au–TiO2 interface. [ABSTRACT FROM AUTHOR]