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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]

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]

CeNi XH ZO Y nano-oxyhydride catalysts were developed for the highly efficient sustainable hydrogen production from ethanol and water in the oxidative steam reforming reaction. After an in situ treatment in hydrogen in the temperature range of 200-300 °C, the cerium-nickel binary mixed oxides became hydrogen reservoirs, which were called oxyhydrides, in the presence of hydrogen species of the hydride nature in the anionic vacancies of mixed oxides. A novel technology was developed for the room temperature hydrogen production by using the chemical energy released from the reaction between CeNi XH ZO Y nano-oxyhydride catalysts and oxygen, which completely converted ethanol specifically at 60 °C (oven temperature) and simultaneously produced hydrogen, carbon dioxide, and carbon monoxide along with small amounts of methane and ethanal. CeNi XH ZO Y nano-oxyhydride catalysts demonstrated excellent catalytic stability, which was attributed to the graphitic filamentous carbon formed during the reaction. The unique activation phenomenon of the reaction (a huge variation in the temperature between the catalyst bed and the oven) was demonstrated in detail. Finally, the correlations among the catalyst properties, the catalytic performances, and the characterizations were thoroughly discussed. [ABSTRACT FROM AUTHOR]

A quasi-homogeneous solution of gold nanoparticles prepared by the Turkevich method was used as an unconventional catalyst in the oxidation of glycerol (GLY) in the liquid phase. The highest obtained conversion was 100 % after 3 h of reaction at 100 °C under an oxygen atmosphere (5 bar). The main products were glyceric, glycolic, formic, tartronic, and oxalic acid with selectivities of 28, 36, 25, 9, and 2 %, respectively. Traces of hydroxypyruvic and acetic acid were also detected (combined selectivities below 1 %). To elucidate the reaction mechanism and specify the role of gold nanoparticles in the oxidation process, a series of experiments under various reaction conditions were carried out. The effect of reaction temperature, oxygen pressure, gold concentration, and GLY/base molar ratio was investigated. All catalytic results were systematically compared to the corresponding noncatalytic base-induced transformations (blank tests). Such an approach allowed us to separate and clarify the respective driving parameters for the transformation of GLY (presence of a base and activity of the gold catalyst). The reaction mechanism comprised a series of oxidation and CC cleavage reactions, whereas additional oxidation-reduction reactions (of the Cannizzaro type) could also occur in the presence of the base. [ABSTRACT FROM AUTHOR]

The transesterification of diethyl oxalate (DEO) with phenol to form diphenyl oxalate (DPO) has been carried out in the liquid phase over very efficient MoO3/TiO2 solid-acid sol-gel catalysts. A selectivity of 100 % with a remarkable maximum yield of 88 % were obtained, which opens the route to downstream phosgene-free processes for the synthesis of polycarbonates. Interpretation of the results of various acidity measurements (NH3 and pyridine desorption, methanol oxidation as a probe reaction) allowed us to identify the catalytic sites as Lewis acid sites. [ABSTRACT FROM AUTHOR]

Taking alcohol from the nanobar The cover picture shows the use of nickel and cerium nano‐oxyhydride catalysts in hydrogen production from ethanol in the presence of water and oxygen. In their Full Paper on p. 2207 ff., L. Jalowiecki‐Duhamel et al. describe the characterization and catalytic properties of the nano‐compounds. Hydrogen production (45 mol %) and total conversion of ethanol remain almost constant over at least 75 h time‐on‐stream with only a small energy input (reaction in oven at 60 °C), thanks to the presence of hydride species stored in the solid. [ABSTRACT FROM AUTHOR]

• Chemical looping dry reforming of methane (CLDRM) is highly selective to syngas. • Ni/CeO 2 carriers are active and selective at high temperature (>650 °C). • Preparation method has limited effect on properties of Ni/CeO 2 carriers. • Co/CeO 2 shows the best selectivity at low temperature (600 °C). • Commercial CeO 2 , iron or zirconia doping show the lowest activity and/or selectivity. Chemical looping dry reforming of methane (CLDRM) consists in reacting CH 4 with an oxygen carrier (OC) to produce syngas and subsequently oxidizing the OC using CO 2. Based on previous work on Ni/CeO 2 , several ceria based OCs are explored. First, different preparation methods are compared. OCs obtained by Ni impregnation on homemade ceria or coprecipitation method show similar results while the use of a commercial ceria leads to an inactive carrier. Second, Zr doping of the carrier is shown to improve the thermal stability of the material but the increased oxygen mobility promotes the total oxidation of methane instead of syngas production. Simultaneously higher amounts of coke are produced. Then, the substitution of Ni by other active elements is explored. Iron doped OC leads to very low CLDRM activity in the temperature range explored (600–800 °C). Furthermore, selectivity is negatively affected as iron oxide can contribute as oxygen carrier together with ceria, contrary to Ni or Co. Finally, substitution of Ni with Co is studied resulting in a lower reactivity towards methane. This proves to be particularly interesting at low temperature (600–650 °C) by providing good balance between surface properties for methane activation and bulk mobility of oxygen species. [ABSTRACT FROM AUTHOR]

Mg 2 AlNi X H Z O Y nano-oxyhydrides formation is evidenced during pre-treatment in H 2 at 450 °C of Mg 2 AlNi X O Y nano-compounds leading to highly performant catalysts in ethanol conversion and H 2 formation, particularly at low temperature, through catalytic steam reforming (SRE) and oxidative steam reforming (OSRE). Total conversion of ethanol is obtained in SRE and OSRE with high stability. A higher production of H 2 (60 L h −1 g cat −1 ) can be achieved at a reaction temperature of 300 °C in OSRE conditions compared to SRE (10 L h −1 g cat −1 ) mainly because of a beneficial use of a high concentration of ethanol (14 mol%) in presence of O 2 . Moreover, carbon formation is decreased and a much lower input of energy of 50 °C is used to get a temperature of 300 °C when O 2 is added. Different physico-chemical characterizations and in particular in H 2 (TPR, H 2 -XRD, INS) and after tests allow to conclude that the presence of Ni 2+ cations in strong interaction with other cations, anionic vacancies and hydride species on and inside the solid play an important role in the catalytic performance (conversion and selectivity) and stability. [ABSTRACT FROM AUTHOR]

For a sustainable society, it is highly desirable to produce H 2 from renewable sources and with low energy consumption. Functional, cheap and easy-prepared Mg 2 AlNi X H Z O Y nano-oxyhydrides materials were successfully developed from Mg 2 AlNi X O Y nano-composites ex-hydrotalcites. After an in situ treatment in H 2 at low temperature (450 °C), the Mg 2 AlNi X O Y nano-composites (x > 1) become hydrogen reservoirs, called oxyhydrides, with the presence of hydrogen species of hydride nature that can be stored in the anionic vacancies of the solid. Advanced techniques in presence of H 2 including TPR, in situ XRD and INS were used to study the nano-composites with different Ni contents. The Mg 2 AlNi X H Z O Y nano-oxyhydrides (x > 1) are shown to be able to simultaneously provide hydride species and to totally convert ethanol and produce H 2 from a water-ethanol mixture in presence of O 2 , with very low energy input. In complement to the exothermic partial oxidation reaction, the chemical energy delivered from the strong exothermic reaction between hydride species and O 2 is used. The reaction is sustainable because hydride species are replaced and provided by ethanol. [ABSTRACT FROM AUTHOR]

Highlights: [•] Co-precipitation method allows obtaining well-tuned NiXMg2AlOY mixed oxides. [•] The effect of Ni content, activation treatment, and reaction conditions are studied. [•] Total conversion of ethanol at 450°C and CO-free H2 production of 3.0molmolEtOH−1. [•] Good catalytic stability even though solid carbon is formed. [•] Active site involves anionic vacancies, O2− species and cations in close interaction. [ABSTRACT FROM AUTHOR]

• Mixed oxides based hydride reservoirs with Ni2+ cations are performant catalysts. • CO 2 conversion overcomes the predicted value at 500−600 °C. • H 2 /CO ratio of 1.3 is obtained at 600 °C. • No carbon formation at 600 °C in O 2 /CH 4 ratio of 0.3. The oxidative dry reforming of CH 4 (ODRM) was studied at 500−800 °C in harsh conditions (CH 4 /CO 2 /O 2 /N 2 = 1:0.7:α:N 2 with 20 % of CH 4 , 96,000 mLh−1g cat −1 and α varying from 0 up to 0.5) on CeNi X Al 0.5 H Z O Y (0.5 ≤ x ≤ 5) nano-oxyhydride catalysts. At low temperature (500−600 °C), the conversion of CH 4 reaches the thermodynamic limit while those of CO 2 overcomes the predicted value in particular at 500 °C. At 600 °C with an O 2 /CH 4 ratio of 0.3, the CeNi 2 Al 0.5 H Z O Y catalyst allows getting CH 4 and CO 2 conversions of about 63 % and 50 %, respectively, and a H 2 /CO ratio of about 1.3, without carbon formation. The physico-chemical characterizations performed before and after test show the existence of strong interactions existing between Ni2+ cations with other cations and the presence of nano-oxyhydride compound. The mixed oxide based nano-materials corresponding to hydride reservoirs with the presence of Ni2+ cations are shown to be highly active, selective and stable catalysts. [ABSTRACT FROM AUTHOR]