Sorption enhanced reaction processes (SERP) were successfully evaluated in the CO2 hydrogenation reaction, by leveraging the sorption benefits to enhance the formation of methanol. In this work, a dedicated experimental protocol and an analytical setup were developed to quantitatively investigate the coupling between reaction and sorption during the transient regime. This system enables the direct quantification of all molecules at the reactor outlet, including methanol and water, thus allowing an accurate real-time mass balance analysis and improved understanding of the phenomena occurring during sorption-enhanced operation.Experiments performed at 230 °C and 30 bar using a Cu / ZnO / Al2O3 commercial catalyst combined with LTA zeolite (4A) demonstrated that sorption significantly enhances methanol production beyond the thermodynamic equilibrium predicted for a conventional reactor, while the impact on CO production remains limited. Substantial adsorption of both water and methanol within the zeolite framework was assessed. Indeed, the LTA sorbent exhibited a methanol sorption selectivity of 31%, which significantly enhanced the total methanol production during the sorption-enhanced effect. Indeed, 56% of the total methanol formed was temporarily retained within the zeolite, highlighting the key role of the methanol sorption in promoting CO2 hydrogenation with respect to the reverse water-gas shift reaction (RWGS), while water removal influences both reactions. As a result of this sorption-enhanced effect, the quantities of methanol and CO produced increased by 168% and 55%, respectively, compared with the reference experiment for a 60 min period. Structural characterization (XRD and 27Al MAS NMR) confirmed that the LTA zeolite framework remained stable after the experiment despite the harsh conditions of high pressure and temperature in the presence of steam.

In this study, we conducted a comprehensive investigation relating to the efficiency of the Al-MOF CAU-10 as a sorbent in a Sorption Enhanced Reaction Process (SERP) based on its hydrophilic/hydrophobic balance. We confirmed both experimentally and through simulation that CAU-10 is a hydrophobic material at low pressure, whereas it shows a high affinity for methanol. The cosorption of water and methanol shows that both molecules are in competition, mostly for the oxygen atoms of the ligands. An important result is the influence of the relative pressure of the vapor mixture on the composition of the adsorbed phase. At low relative pressure, methanol is mostly adsorbed from the mixture, while water is only adsorbed from 0.16 p/p°. At higher relative pressures, water becomes predominant in the adsorbed phase. We therefore took advantage of this result to improve the catalytic reduction of CO2 into methanol by sorption of methanol or water. The catalytic test was performed at 270 °C under a total pressure of 50 bar. Under these conditions, the methanol yield increased by more than 6% compared to a catalytic reaction performed without sorbent, thus validating our fundamental approach.

The hydrogen energy vector offers a great potential for enhancing intermittent renewable energy systems, which are expanding rapidly. Hydrogen can be produced by electrolysis using renewable electricity and then used in fuel cells for energy storage and transport. This ensures energy availability when renewable sources are inactive or far from consumption areas. Currently, polymer membrane fuel cell systems are technologically advanced but still require high purity hydrogen. In contrast, Solid Oxide Fuel Cells (SOFCs) are less mature, but operate at high temperatures and use either anionic or proton conduction. They can utilize different fuels, such as syngas from biomass gasification, and operate in reversible modes, switching between electrolyzer and generator operation [1]. This study focuses on new anode materials for solid oxide fuel cells operating at high temperatures, specifically on the family of (Ce 1-x M x ) 0.95 Ni 0.05 O 2- δ , (M=Gd or Sm, denoted CMNx), synthesized by the combustion method. This presentation will highlight the favourable electrochemical properties of these samples by using electrochemical impedance spectroscopy under a humidified mixture of H2/Ar (5/95). Symmetric cells based on these compounds showed excellent performance, with an area-specific resistance (ASR) related to charge transfer and mass transfer below 0.5Ω·cm² at 700°C for all of them. The Nyquist diagrams plotted at Open circuit voltage for Ce 0.95 Ni 0.05 O 1.95 at 700°C, 650°C, 600°C is given as figure 1. Their stability will be also examined. Results obtained by the cermet Ce 0.63 Zr 0.33 Sm 0.04 O 1.99 - Ni (10 wt %), prepared by ICPEES (Institut de Chimie et Procédés pour l’Energie, l’Environnement et la Santé) as part of FLEXISOC project, will be also presented. Their performance as an anode in a complete fuel cell prepared with YSZ (Zr 0.85 Y 0.15 O 1.93 ) as electrolyte and LSM (La 0.6 Sr 0.4 MnO 3 ) as cathode show promising results. [1] Singh, M. (2021). Int. J. Hydrog. Energy , 46 (54), 27643-27674. The authors acknowledge support from the French National Research Agency (ANR) under France 2030 program and reference ANR- 22-PEHY-0003 (project PEPRH2) Figure 1

The use of synthetic natural gas (SNG) as a plug-and-play fuel coming from renewables can help to overcome the limitations given by the intermittency of renewable energy. A way to implement the production of SNG pass through the co-electrolysis of CO2 to a mixture of hydrogen, carbon monoxide and carbon dioxide, steam and small amounts of methane, followed by CO and CO2 methanation. The presence of different reactants and processes requires the comprehension and quantification of the kinetics of the reactions involved with the aim of optimizing methanation. In this work a kinetic model that considers both the direct CO2 methanation and the indirect RWGS + CO methanation pathways has been developed over a Ni(10 %wt)/Ce0.33Zr0.63Pr0.04O2. The kinetic study made it possible to understand the influence of the reactants and products on the reactions through the calculation of reaction rates. This allowed to test, by linearization, the models found in the literature and their adjustment permitted to calculate sixteen kinetic parameters (activation energies, heats of adsorption and pre-exponential factors) present in the rate laws of methanation of CO2, CO and the Reverse Water Gas Shift reaction. The models then made it possible to simulate the evolution of partial flow rates in an isothermal plug flow reactor and were compared to experimental data.

The use of liquid organic hydrogen carriers (LOHC) for hydrogen storage has technical, economical, and environmental advantages. The gamma -butyrolactone (GBL)/1,4-butanediol (BDO) pair is used in this work as a bio-based LOHC. Reaction kinetics of liquid phase GBL hydrogenation and BDO dehydrogenation have been studied using a semi -batch reactor filled with a copper based methanol catalyst with the experiments have been performed in the temperature range of 458 - 503 K with a constant pressure of 50 and 3 bar for hydrogenation and dehydrogenation respectively. Based on analytical results, a reaction pathway including the formation of side products was proposed. This pathway includes the formation of two side -products: 4-hydroxybutyl 4-hydroxybutanoate (4HHB) is produced from the transesterification of GBL by BDO in both reactions; and dibutyleneglycol (DG) from the etherification of BDO in dehydrogenation. Based on experimental results, kinetic models were established for hydrogenation and dehydrogenation reactions. In these models, balanced reactions with a first order were used. Estimation of kinetic parameters for both reactions allows a good prediction of the experimental data and results in a temperature extrapolation by an Arrhenius law. Activation energies for GBL hydrogenation and BDO dehydrogenation were determined to be respectively 104 kJ/mol LOHC and 98.3 kJ/mol LOHC . Furthermore, models are valid at short (up to 5 h) and long (up to 20 h) reaction times and the estimation results display acceptable uncertainties for all the reaction temperatures.

Ternary Cu/ZnO/Al2O3 and Cu/ZnO/CeO2 catalysts were prepared by polyol method and tested for gas-phase low-temperature methanol synthesis from hydrogenation of CO2. The catalysts were characterized by N2 physisorption, SEM–EDX, XRD, H2-TPR and XPS. The activity of the catalysts was evaluated in a fixed-bed micro-reactor at atmospheric pressure and 40 bar at different reaction temperatures, and H2/CO2 ratio of 3:1. The results showed that the nature of the promoter influenced the physicochemical properties of the catalysts as well as the catalytic activity and product selectivity. Compared with ternary Cu/ZnO/Al2O3 catalyst, Cu/ZnO/CeO2 catalyst indicated that modifcation of CuO/ZnO catalyst with CeO2 promoted the CuO dispersion, reduced the CuO crystallite size, decreased the reduction temperature of highly dispersed CuO, decreased the activation energy and improved the catalytic activity of the Cu/ZnO/CeO2 catalyst.

Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption. The 13X zeolite was found to be strongly acidic (BrØnsted acid sites, Si/Al = 1.3) and its specific surface area around 1100 m2·g−1. Water was found to be able to diffuse within both the supercages and the sodalite cavities of the FAU structure, whereas methanol and cyclohexane were confined in the supercages only. The water/methanol sorption selectivity of the 13X zeolite was demonstrated by co-adsorption measurements. The composition of the water/methanol adsorbed phase could be calculated by assuming IAST hypotheses. This model failed in the case of the water/cyclohexane co-adsorption system, which is in line with the non-miscibility of the components in the adsorbed state. The sorption isotherms could be successfully simulated, confirming the robustness of the forcefields used. The 13X zeolite confirmed its a priori expected hydrophilic nature, which is useful for the selective adsorption of water in a methanol–water vapor mixture.

Perovskites refer to ceramic materials with an ABO3 structure. The optimization of synthesis parameters and material composition can enhance the catalytic efficiency in various chemical reactions, such as dry methane reforming. In order to highlight the differences in the catalytic properties, this study aims to compare three synthesis methods (citrate, auto-combustion and Pechini) for a same perovskite formulation namely SrZr0 & sdot;5Ni0 & sdot;4Fe0 & sdot;1O3. The crystal structure and reducibility profile are determined by XRD and TPR experiences respectively. Surface properties and composition are identified by chemisorption tests (allowing the study of basicity and nickel dispersion) and XPS analyses, respectively. Isothermal catalytic experiences from 600 to 750 degrees C, under atmospheric pressure and for a WHSV of 40 L/(h.g) together with stability tests for 25 hat 750 degrees C were conducted. The outcomes show the importance of properly choosing the perovskite preparation methods in order to achieve the desired surface, structural and reactivity properties.

This paper compares different power-to-methanol process configurations encompassing the electrolyser, adiabatic reactor(s) and methanol purification configurations.

Catalytic structuration on SiC extrudates improves the catalytic performance of Ni based catalysts in toluene reforming, and provides promising materials for hot gas cleaning in biomass gasification.

Mixed Ce−Zr oxides with a fluorite structure were synthesized by the solvothermal method in a supercritical medium of isopropanol. The prepared mixed oxides Ce0.5Zr0.5O2 and Ce0.75Zr0.25O2 were used as supports for 5 wt%Ni and bimetallic 2.5 wt%Ni+2.5 wt%Co catalysts. The catalysts were fully characterized (specific surface area, morphology, particle size, phase composition, surface atomic composition) and tested in ethanol dry reforming.

The kinetics of methanol synthesis remains debatable for various reasons, such as the lack of scientifically conclusive agreement about reaction mechanisms. The focus of this paper is on the evaluation of the intrinsic kinetics of the methanol synthesis reaction based on CO2 hydrogenation and the associated reverse water–gas shift as overall reactions. The industrial methanol synthesis catalyst, Cu/ZnO/Al2O3/MgO, was used for performing the kinetic studies. An optimal kinetic model was assessed for its ability to predict the experimental data from differential to integral conditions, contrary to the typical fitting of only the integral conditions’ data (common practice, as reported in the literature). The catalyst testing and kinetic evaluations were performed at various temperatures (210–260 °C) and pressures (40–77 bar), and for different stoichiometric numbers (0.9–1.9), H2/CO2 ratios (3.0–4.4) and carbon oxide ratios (0.9–1.0), in an isothermal fixed bed reactor, operated in a plug-flow mode. Experiments with CO in the feed were also generated and fitted. Different literature kinetic models with different assumptions on active sites, rate-determining steps, and hence, model formulations were fitted and compared. The original Seidel model appeared to fit the kinetic data very well, but it has twelve parameters. The modified model (MOD) we propose is derived from this Seidel model, but it has fewer (nine) parameters—it excludes CO hydrogenation, but it takes into consideration the morphological changes of active sites and CO adsorption. This MOD model, with three active sites, gave the best fit to all the data sets.

CuO-ZnO-ZrO2 catalysts were synthetized by controlled continuous coprecipitation in a microfluidic reactor. CuO, ZnO and ZrO2 contents in catalysts were kept constant at 37.5 wt% of CuO (corresponding to 30% Cu0), 41.0 wt% of ZnO and 21.5 wt% of ZrO2. Numerous parameters of the continuous microfluidic coprecipitation, such as the nature of the carrier fluid, the residence time in the microfluidic synthesis reactor, the reagents flow rates during the synthesis and the pH, were studied in order to obtain perfectly homogeneous catalytic materials. All catalysts were characterized and then tested in methanol synthesis via CO2 hydrogenation on the REALCAT platform using high-throughput experiments. The optimum catalytic results were obtained for the catalyst synthesized by the continuous coprecipitation in a microfluidic reactor at following controlled parameters: water as carrier fluid, 30 s of residence time, low total reagent flowrate of 35 mu L min-1 and pH equal to 8. This catalyst presented a good CO2 conversion of 21.4 % along with a methanol selectivity of 33 %, leading to a record methanol productivity of 1135 gMeOH kgcat-1 h-1 at 280 degrees C, 50 bar and a GHSV of 25,000 h-1 (STP).

Three Ni-based catalysts (Ni/CY, Ni/LSCF and RuNi/LSCF) were submitted to a pre-treatment in a gas atmosphere generated during biomass gasification process. The modifications of the physicochemical properties and the catalytic performance of the catalysts pre-treated in a model ex-biomass gas were compared with catalysts pre-treated in H2. The generation of Ni0 through the pre-treatment in a model ex-biomass gas was evidenced. This pre-treatment also provoked the formation of whisker carbon deposits at the catalytic surface and a change in the Ni dispersion by comparing with the reduction in H2. The catalytic performance in WGS, CO methanation and toluene reforming of the catalysts was evaluated. Both Ni catalysts exhibited activity in WGS and CO methanation in the absence of toluene. However, these catalysts underwent deactivation in presence of toluene, becoming inactive in reforming reaction. Ru was found to improve this catalytic activity by enhancing the resistance to coke and Ni oxidation.

The structure of catalyst containing Ni nanoparticles (NPs) supported over carbon nanofibers/few layer graphene (CNFs/FLG) was tailored via modification of chemical vapor deposition parameters in view of methanation of CO2 under induction heating mode (IH). High edges-to- graphitic plane ratio in the support achieved due to the specific herringbone morphology of CNFs allowed to get high CO2 conversion of 85 % at relatively low temperature (360 degrees C) at very low Ni loading of only 10 %. A design of catalyst included also the use of FLG known for high temperature conductivity and by occasion serving as a support to grow CNFs. The performances of certain catalysts are also tested under "standard" Joule heating in order to check the role of the magnetic and conductive carbon support. The morphology, chemical composition and SAR measurements of the catalysts and carbon supports themselves are addressed and their structure-catalytic performances are discussed.

Designing an economically viable catalyst that maintains high catalytic activity and stability is the key to unlock dry reforming of methane (DRM) as a primary strategy for biogas valorization. Ni/Al2O3 catalysts have been widely used for this purpose; however, several modifications have been reported in the last years in order to prevent coke deposition and deactivation of the samples. Modification of the acidity of the support and the addition of noble metal promoters are between the most reported strategies. Nevertheless, in the task of designing an active and stable catalyst for DRM, the selection of an appropriate noble metal promoter is turning more challenging owing to the lack of homogeneity of the different studies. Therefore, this research aims to compare Ru (0.50 and 2.0%) and Re (0.50 and 2.0%) as noble metal promoters for a Ni/MgAl2O4 catalyst under the same synthesis and reaction conditions. Catalysts were characterized by XRF, BET, XRD, TPR, hydrogen chemisorption (H2-TPD), and dry reforming reaction tests. Results show that both promoters increase Ni reducibility and dispersion. However, Ru seems a better promoter for DRM since 0.50% of Ru increases the catalytic activity in 10% and leads to less coke deposition.

Ni addition over two ceria-based mixed oxides (Ce0.63Zr0.33Sm0.04O2- delta, and Ce2Y2O7) has been carried out by sol-gel (Ni-CZS and Ni-CY) and wet impregnation (Ni/CZS and Ni/CY) methods. The four catalysts were characterized by BET, XRD, TGA, XPS, H-2-TPR and H-2-chemisorption. Partial insertion of Ni2+ ions into both mixed oxide's structure was found in the corresponding sol-gel catalysts. Their catalytic activity was evaluated in tar reforming, with toluene and phenol as model molecules, under isothermal condition at 400 and 550 degrees C for 6 h, using a typical ex-biomass syngas composition in order to mimic the real conditions of a gasification process. Among the four materials, Ni/CY was the best catalyst in terms of average tar conversion, whereas the best catalytic stability was obtained for Ni-CZS, owing to inserted Ni2+ species. This study demonstrates that Ni/CY can be a promising system for tar abatement at relatively low temperature through catalytic hot gas cleaning of a raw syngas generated by biomass gasification.

Ordered mesoporous MgAl2O4 support was synthesized by one-pot evaporation-induced self-assembly method with block copolymers. Nanocomposite catalysts were prepared by loading this support with PrNi0.9Ru0.1O3 perovskite or Ni + Ru-doped Ce0.35Zr0.35Pr0.3O2 fluorite oxides. Their texture, structure, surface properties and reactivity have been studied by combination of modern structural, spectroscopic and kinetic methods. Suppression of MgAl2O4 support acidity, strong interaction of small Ru-Ni alloy nanoparticles with the surface layers of this support modified by perovskite and fluorite oxides with a high oxygen mobility and reactivity provide a high activity and stability to coking and sintering of these catalysts in all studied reactions of methane and ethanol transformation into syngas. Ni + Ru/Ce0.35Zr0.35Pr0.3O2/MgAl2O4 active component loaded on honeycomb Fechraloy foil substrate demonstrated a high performance and stability to coking in autothermal natural gas oxi-dry reforming, ethanol steam reforming and autothermal reforming of ethyl acetate in concentrated feeds promising for the practical application.

Synthetic natural gas (SNG) is an efficient option for transforming renewable energy into carbon-neutral fuels while using a plug-and-play infrastructure, supporting the transition to renewable energy, paving the way for a hydrogen-based economy. Captured CO2 can be processed with water through hightemperature co-electrolysis, where reduction to CO and H-2 production by water splitting occurs. The outlet gas, composed of CO2, CO, H-2, and small amounts of CH4, can be used to produce SNG by methanation of CO and CO2 with hydrogen. Among the parameters influencing the methanation reactions, the characteristics of the support and its interaction with the metallic active phase, usually Ni, are of crucial importance and can be tuned by the synthesis of the support. For this reason, three different synthetic methods, namely, pseudo sol-gel, coprecipitation, and colloidal combustion, were applied to the synthesis of a Ce/Zr/Pr oxide. The supports were fully characterized by nitrogen physisorption, X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), temperature-programmed reduction (TPR), and H-2 temperatureprogrammed desorption (H-2-TPD) before and after impregnation with 10 wt % Ni. The coprecipitated catalyst exhibited the best performances when subjected to CO2/CO co-methanation and typical post-co-electrolysis mixture, thanks to a combination of different characteristics such as high surface area and mesoporosity, which allowed good Ni dispersion and surface area, high support metal interaction, and reducibility. Finally, the effect of Pr seemed to be beneficial, increasing the methane yield at low temperatures.

Methanol adsorption over both supported NiSn Nps and analogous NiSn catalyst prepared by impregnation was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to gain insights into the basis of hydrogen production from methanol steam reforming. Different intermediate species such as methoxides with different geometry (bridge and monodentate) and formate species were identified after methanol adsorption and thermal desorption. It is proposed that these species are the most involved in the methanol steam reforming reaction and the major presence of metal-support interface sites in supported NiSn Nps leads to higher production of hydrogen. On the basis of these results, a plausible reaction mechanism was elucidated through the correlation between the thermal stability of these species and the evolution of the effluent gas released. In addition, it was demonstrated that DME is a secondary product generated by condensation of methoxides over the acid sites of alumina support in an acid-catalyzed reaction.