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The CO2 methanation catalyzed by supported metals has been widely investigated. In spite of its apparent simplicity, there are still open questions regarding its mechanism, with apparently contradictory proposals that rely mainly on infrared (IR) spectra of functioning catalysts. Here we review the various mechanistic proposals for the reaction. Special focus is made on the following questions: (a) what is the actual physical evidence of adsorbed species present on the catalysts?, (b) how can reaction intermediates be distinguished from spectators?, (c) what is the identity of the active site(s) for the reaction, and (d) could multiple reaction routes occur simultaneously on the catalysts? Kinetic models of the reaction and a survey of the apparent contradictions in the interpretation of IR spectra characterizing functioning catalysts are also presented.

In this study, zeolites prepared by the hydrothermal method from Ecuadorian clay were combined with the precursor clay and with the semiconductor ZnTiO3/TiO2 prepared by the sol-gel method to adsorb and photodegrade cyanide species from aqueous solutions. These compounds were characterized by X-ray powder diffraction, X-ray fluorescence, scanning electron microscopy, energy-dispersive X-rays, point of zero charge, and specific surface area. The adsorption characteristics of the compounds were measured using batch adsorption experiments as a function of pH, initial concentration, temperature, and contact time. The Langmuir isotherm model and the pseudo-second-order model fit the adsorption process better. The equilibrium state in the reaction systems at pH = 7 was reached around 130 and 60 min in the adsorption and photodegradation experiments, respectively. The maximum cyanide adsorption value (73.37 mg g−1) was obtained with the ZC compound (zeolite + clay), and the maximum cyanide photodegradation capacity (90.7%) under UV light was obtained with the TC compound (ZnTiO3/TiO2 + clay). Finally, the reuse of the compounds in five consecutive treatment cycles was determined. The results reflect that the compounds synthesized and adapted to the extruded form could potentially be used for the removal of cyanide from wastewater.

5-Hydroxymethylfurfural (HMF) is a biobased platform chemical that can be valorized into a spectrum of valuable products. In this report, supported Ir, Ir–Co, Ir–Ni, and Ir–Ru catalysts were investigated for this purpose. Only hydrogenation of HMF to 2,5-bis-(hydroxymethyl)furan (BHMF) occurred over all catalysts. The effect of the second metal (Co, Ni, and Ru) on Ir/SiO2 was reflected by the kinetic constants being in the order Ir–Ni/SiO2 > Ir–Co/SiO2 > Ir–Ru/SiO2. The oxophilic nature of the secondary metal improved the catalytic performance of the bimetallic catalysts compared to the monometallic iridium catalyst (Ir/SiO2). Addition of HCOOH and H2SO4 as cocatalysts is a strategy to reach one-pot conversion of HMF to 2,5-di-methylfuran (DMF). Over-hydrogenolysis products such as 2,5-dimethyltetrahydrofuran were formed when only H2SO4 was added, giving higher activity compared to addition of HCOOH. Simultaneous presence of acids gave the highest HMF conversion, promoting esterification to 5-formyloxymethyl furfural and allowing the one-pot transformation of HMF to DMF. Thermodynamic analysis of HMF transformations revealed that both hydrogenation and dehydration steps are feasible.

On the occasion of his 80th birthday, we take stock of the remarkable and ongoing career of Professor Bruce C. Gates. This Account highlights his key scientific achievements in three areas of significance: supported metal clusters and atomically dispersed metal complexes, hydroprocessing reaction networks and catalysts, and strong acid catalysis. His contributions in all three areas are noteworthy and have been sustained over 50 years. The work of his group evolved from mainly catalyst synthesis and reaction studies to also incorporate sophisticated characterization techniques based on X-ray absorption spectroscopies and improved scanning transmission electron microscopic examination of catalytic surfaces. In the course of this work, he has addressed, and contributed to the solutions of some of the most significant and challenging problems in catalysis of the last half century., NA

Density functional theory (DFT) is a widely used method for studying matter at the quantum level. In this study, the surface (101) of TiO

A serie of supported bimetallic MoRe carbides were prepared with different Mo/Re molar ratio by using a mixture H2+ C2H4 at 700 °C and compared to the respective monometallic carbides in the guaiacol conversion at 350 °C, 5.0 MPa. Catalysts were characterized by N2-physisorption, CO-chemisorption, temperature programmed reduction/desorption of NH3 (TPR and TPD-NH3 respectively) and XPS. The results have shown an enrichment of Re at the surface occur suggesting that Re carbide recovered Mo carbide particles and, thus improving Re dispersion. This was traduced by an enhancement of the initial rate of conversion of the bimetallic catalyst. A synergistic effect between Mo and Re carbide was reported from XPS results and led to the activation of the demethylation of guaiacol to catechol.

Mesoporous carbonaceous materials were functionalized with iron or copper by a mechanochemical approach. The structural and textural properties of these catalysts were characterized by N2 physisorp...

8 figures, 4 tables. supplementary information avilable.-- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0, The main aim of the present study is to provide a comprehensive assessment of the effects of process activation conditions on the textural properties of the resulting activated carbons, which were produced from wheat straw-derived biochar through chemical activation (with K2CO3 at different pressures and mass impregnation ratios) and physical activation (with CO2 at different temperatures and pressures). For chemically activated biochars, it was found that specific surface area and pore size distribution were both only positively affected by increasing the carbonate loading. However, physically activated biochars produced at the highest pressure and lowest temperature (1.0 MPa and 700 °C) had the highest surface areas and widest pore size distributions. The materials with the most appropriate textural properties were then tested as catalysts for steam and dry reforming of the aqueous phase of pyrolysis oil. The best catalytic performance (a total gas yield of 74% and a selectivity toward H2 of almost 40%) was observed for a physically activated biochar. This good performance was ascribed to the high availability of K0 on the catalyst surface, which could effectively promote the reactions involved in the upgrading process., This project received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 721991. The authors also acknowledge the funding from the Aragón Government (Ref. T22_20R), co-funded by FEDER 2014-2020 “Construyendo Europa desde Aragón”. This study was partly supported by the French PIA project “Lorraine Université d’Excellence”, reference ANR-15-IDEX-04-LUE, PROMOTEE project and TALiSMAN project, funded by FEDER (2019-000214).

We assess the performance of mRNA capture sequencing to identify fusion transcripts in FFPE tissue of different sarcoma types, followed by RT-qPCR confirmation. To validate our workflow, six positive control tumors with a specific chromosomal rearrangement were analyzed using the TruSight RNA Pan-Cancer Panel. Fusion transcript calling by FusionCatcher confirmed these aberrations and enabled the identification of both fusion gene partners and breakpoints. Next, whole-transcriptome TruSeq RNA Exome sequencing was applied to 17 fusion gene-negative alveolar rhabdomyosarcoma (ARMS) or undifferentiated round cell sarcoma (URCS) tumors, for whom fluorescence in situ hybridization (FISH) did not identify the classical pathognomonic rearrangements. For six patients, a pathognomonic fusion transcript was readily detected, i.e., PAX3-FOXO1 in two ARMS patients, and EWSR1-FLI1, EWSR1-ERG, or EWSR1-NFATC2 in four URCS patients. For the 11 remaining patients, 11 newly identified fusion transcripts were confirmed by RT-qPCR, including COPS3-TOM1L2, NCOA1-DTNB, WWTR1-LINC01986, PLAA-MOB3B, AP1B1-CHEK2, and BRD4-LEUTX fusion transcripts in ARMS patients. Additionally, recurrently detected secondary fusion transcripts in patients diagnosed with EWSR1-NFATC2-positive sarcoma were confirmed (COPS4-TBC1D9, PICALM-SYTL2, SMG6-VPS53, and UBE2F-ALS2). In conclusion, this study shows that mRNA capture sequencing enhances the detection rate of pathognomonic fusions and enables the identification of novel and secondary fusion transcripts in sarcomas.

The abnormal implantation of the trophoblast during the first trimester of pregnancy precedes the appearance of the clinical manifestations of preeclampsia (PE), which is a hypertensive disorder of pregnancy. In a previous study, which was carried out in a murine model of PE that was induced by NG-nitro-L-arginine methyl ester (L-NAME), we observed that the intravenous administration of fibroblast growth factor 2 (FGF2) had a hypotensive effect, improved the placental weight gain and attenuated the fetal growth restriction, and the morphological findings that were induced by L-NAME in the evaluated tissues were less severe. In this study, we aimed to determine the effect of FGF2 administration on the placental gene expression of the vascular endothelial growth factor (VEGFA), VEGF receptor 2 (VEGFR2), placental growth factor, endoglin (ENG), superoxide dismutase 1 (SOD1), catalase (CAT), thioredoxin (TXN), tumor protein P53 (P53), BCL2 apoptosis regulator, Fas cell surface death receptor (FAS), and caspase 3, in a Sprague Dawley rat PE model, which was induced by L-NAME. The gene expression was determined by a real-time polymerase chain reaction using SYBR green. Taking the vehicle or the L-NAME group as a reference, there was an under expression of placental VEGFA, VEGFR2, ENG, P53, FAS, SOD1, CAT, and TXN genes in the group of L-NAME + FGF2 (p < 0.05). The administration of FGF2 in the murine PE-like model that was induced by L-NAME reduced the effects that were generated by proteinuria and the increased BP, as well as the response of the expression of genes that participate in angiogenesis, apoptosis, and OS. These results have generated valuable information regarding the identification of molecular targets for PE and provide new insights for understanding PE pathogenesis.

[EN] We have studied the direct synthesis of hydrogen peroxide using a catalytic system consisting of palladium supported on silica bifunctionalized with sulfonic acid groups and bromide in the absence of acid and halide promoters in solution. Catalysts with several bromide substituents were employed in the catalyst synthesis. The prepared samples were characterized by TXRF, XPS, and hydrogen peroxide decomposition. Catalysts characterization indicated the presence of only palladium (II) species in all of the samples, with similar values for surface and bulk of Pd/Br atomic ratio. The catalysts were tested via direct synthesis, and all samples were able to produce hydrogen peroxide at 313 K and 5.0 MPa. The hydrogen peroxide yield and selectivity changed with the Pd/Br ratio. A decrease in the Pd/Br ratio increases the final hydrogen peroxide concentration, and the selectivity for HO reaches a maximum at a Pd/Br ratio around 0.16 and then decreases. However, the maximum hydrogen peroxide concentration and selectivity occur at slightly different Pd/Br ratios, i.e., resp. 0.4 vs. 0.16., This research was funded by SOLVAY (Brussels).

6 Figures, 1 Table.-- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, The competitiveness of European coal tar distillation plants could be improved by the revaluation of coal-derived liquids and rejects such as phenolic oils, which currently lack high-end applications. In this study, carbon gels were successfully prepared for the first time from phenolic oil by base-catalysed sol-gel polymerisation, by taking advantage of all the major components of phenolic oil rather than the pure, single-component phenolic precursors that are normally used in sol-gel routes. To increase the feasibility of industrial applications, the organic gels were dried under subcritical conditions and the resultant xerogels were submitted to carbonisation and chemical activation in a one-step process, using different KOH to organic gel mass ratios. The resultant ACs were applied as supercapacitor electrodes and attained higher electrochemical performances than carbon gels previously obtained from classic precursors: high capacitance retention up to 74.9% at 12 A g−1, energy and power densities up to 7.37 W h kg−1 and 5.70 kW h kg−1, respectively, high cycling stabilities up to 94.8% after 10,000 charge-discharge cycles, high rate capability of 66% under 1 V s−1 scan rate, and fast frequency response of 0.45 s., The IJL research team gratefully acknowledges the financial support of PROMOTEE 2016-2020, “Functional Porous Carbon Materials Derived from Coal Tar for Energy and Environmental Applications”, through the funds of the European Commission and the Research Fund for Coal & Steel. Dr. A. Sanchez-Sanchez acknowledges the CNRS for financing her post-Doctoral contract.

A series of BiVO4/TiO2 nanocomposites with high surface area have been synthesized by a sol–gel method combined with supercritical drying. BiVO4/TiO2 samples with different BiVO4 loadings were synthesized in order to study the effect of this variable on the structuration and development of BiVO4/TiO2 heterojunctions. Bare BiVO4/TiO2 composites are practically inactive for the photoproduction of hydrogen from ethanol under simulated solar light but their photoactivity notably improves after platinum (Pt) deposition. The photocatalytic activity of the Pt–BiVO4/TiO2 composites was determined by the BiVO4/TiO2 ratio that modifies the interfacial charge transfer efficiency between BiVO4 and TiO2 and also by the Pt loading that controls the dispersion and contact of the Pt particles with the composites. In particular, the composite with 0.5 wt% of Pt attained the optimal H2 evolution rate, which is more than 100 times higher than that of the pristine BiVO4/TiO2 composite. The photoactivity of the Pt–BiVO4/TiO2 composites was explained according to the Z-scheme mechanism in which the electrons from the CB of TiO2 reduced H+ to form H2 through the Pt particles preferentially deposited on it.

Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 11180121 1180982 FONDEQUIP EQM 160070 PIA CCTE AFB 170007 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) 21170881 ANID - Millennium Science Initiative Program NCN17_040 University of Chile in the framework of U-Inicia UI 013/2018

We present a Pt/ZrO2 catalyst that can operate in the harsh conditions of methane oxidation without being deactivated by SO2. XPS analysis of 1%Pt/ZrO2 catalyst revealed the presence of stable Pt2+–Pt4+ and Pt2+–Zr4+ bifunctional catalytic sites of dipolar nature at the Pt–ZrO2 interface. These sites increase the probability of CH4 polarization, increasing the strength of their collision with the catalyst surface, lowering the C–H bond energy and facilitating the abstraction of the first hydrogen in adsorbed CH4. The resistance of the catalyst to deactivation by sulfur poisoning is explained considering the stronger interaction of SO2 with Pt2+–Zr4+ dipolar sites, presenting a higher dipolar electric potential than Pt2+–Pt4+, on which CH4 adsorption and oxidation occur.

The effect of the reduction temperature (300 °C, 400 °C, 500 °C and 600 °C) in cobalt SiO2 core-shell catalysts for chemoselective hydrogenation of cinnamaldehyde is reported. The Co-CoO@SiO2 catalysts structures were synthesized starting from a calcined Co3O4@SiO2 nanostructure obtained using a solvothermal method for the core (Co3O4) and a modified Stober method for the porous shell (SiO2) submitted to different reduction temperatures. The initial Co3O4@SiO2 structure and the derived Co-CoO@SiO2 catalysts were characterized by AAS, TG/DTG, TPR, TEM, XRD, XPS and SBET. The increase in the metallic Co content along with the reduction temperature increased the total conversion of cinnamaldehyde in the liquid-phase hydrogenation reaction. The highest selectivity towards the unsaturated alcohol over Co-CoO@SiO2-500 °C catalyst was attributed to an optimum Co/CoO surface ratio. A large chemical and mechanical stability of the Co-CoO@SiO2 structure was evidenced after five consecutive reaction cycles, revealing the beneficial effect of the core-shell architecture towards cobalt leaching in liquid-phase reactions.

In the present work, the preparation and use of new supported transition metal carbides as catalyst for the conversion of guaiacol was investigated. Several metals (Mo, Re, Ru, Ni, Fe, and Cu) were impregnated over activated carbon and carburized under a mixture of H2/C2H4 at 700 °C. Catalysts were characterized by XRD, N2 physisorption, XPS, CO chemisorption, and TPR-MS. Evidence for carbide formation was obtained in the case of Mo, Re, Ni and Ru, based primarily on CO formation during the TPR-MS analysis. It was found that carbides were mainly active for primary guaiacol conversion to phenol and catechol through demethoxylation and demethylation. Completely deoxygenated products such as benzene and cyclohexane were also formed. The highest selectivity in benzene was obtained for the Re-TPR catalyst while Ni-TPR was the most hydrogenative one.

This contribution describes the modification in the structure and activity of Cu/ZnO catalyst in the methanol synthesis reaction induced by the co-modification with a low amount of Al and Ga (Al+Ga=3% atom). To elucidate the effect of the co modification, the catalysts were characterized by means of variety of techniques (XRD, N2 physisorption, FTIR, TGA, TEM, TPR and N2O chemisorption) and tested in the methanol synthesis reaction carried out in a flow reactor at 250 °C and total pressure of 3 MPa using syngas. The combined characterization and activity tests demonstrated that the co-doping with Al and Ga affects the structure and activity of Cu/ZnO catalysts in a different manner depending on the Al/Ga ratio used. The best catalyst co-loaded with Ga and Al in equal amount shows an improvement in the activity for methanol synthesis respect to the activity obtained on catalysts individually loaded with Al and Ga. The difference in the activity of the samples co-loaded with Al and Ga normalized by N2O chemisorption point to a different participation of the copper surfaces in combination with the defect sites of ZnO depending on the Al and Ga loading., The present investigation was performed within the research program CTQ2016-76505-C3-1 supported by the Spanish Ministry of Science, Innovation and Universities. Elena Millán would like to acknowledge the FPI programme from Spanish Ministry of Science, Innovation and Universities for the research grant.

This study describes the synthesis of palladium-promoted Co@SiO2 catalyst developed by electrostatic immobilization of Pd ionic precursor onto Co3O4 nanoparticles core, coated with a mesoporous SiO2 shell. The oxidized Pd-Co3O4@SiO2 (xPdCo-ox) and partially reduced Pd-Co@SiO2 (xPdCo-red) nanocatalysts were used in the direct synthesis of chloro-arylamines from chloronitroarenes employing heterogeneous hydrogenation process. The effect of palladium content (xPdCo; x = 0.0, 0.5, 1.0 and 3.0 Pd wt%) in the Co3O4 core of the structures on catalytic performance for the hydrogenation of 4-chloronitrobenzene (CNB) to 4-chloroaniline (CAN) was systematically studied. It was found that the incorporation of palladium ionic precursor promotes both Co3O4 core nanoparticles flocculation and an increase in the mesoporous shell thickness in the Pd-promoted catalysts compared to the pristine Co-SiO2 core-shell structure. The TPR, XRD, XPS and magnetic measurements results indicated that the palladium addition promoted the reduction of Co3O4 core during the isothermal H2 treatment at 873 K rendering metallic Pd° and Co° species. The catalytic CNB hydrogenation experiments showed that the 0.5PdCo-red catalyst inhibited both the hydrodechlorination and intermediates accumulation reaching 99% yield in CAN compared to 1.0PdCo-red and 3.0PdCo-red catalysts which provided aniline as undesired product. Additionally, the 0.5PdCo-red catalyst was easily recycled with a moderate catalytic activity after five consecutive reaction cycles. Finally, the catalytic hydrogenation performance of the 0.5PdCo-red catalyst for different pharmaceutical substituted chloro-nitroarenes such as 1-(4-chlorophenoxy)-2-nitrobenzene, 2-chloro-1-((3-fluorobenzyl)oxy)-4-nitrobenzene and 2-chloro-5nitrobenzotrifluoride was also evaluated and revealed high activity (>99% at 3 h of reaction) and selectivity towards the desired chloro-arylmines production, highlighting the potential of this catalyst in these processes.

The synthesis of anatase TiO

Thisworkreportstheexperimentallystudiedmechanochem ica lformationof rhodacyclesby ballmillingpyridine- andquinoline- derivedsubstratesand[Cp*RhCl2]2inthe presenceof NaOAc.Ex-situanalysisof the mechanochem- icalreactionsusingpowderX-raydiffraction(PXRD), solid- stateUV-visspectroscopyandATR- FTIRspectroscopyre- vealedtheformationof unexpectedcocrystalsbetweenthesubstratesandthe rhodiumdimerpriorto the CH activationstep.Thissequenceof eventsdiffersfromthegenerallyacceptedstepsin solutionin whichcleavageof [Cp*RhCl2]2isinitiatedby acetateions.Additionally, the mechanochemicalapproachenabledthe synthesisof the six-memberedrhoda-cycle[Cp*Rh(2- benzilpyridine)Cl], a metalcomplexrepeatedlyreportedas inaccessiblein solution.Altogether, the resultsofthisinvestigationclarifysomeof the fundamentalaspectsofmechanochemicalcyclometallatio ns.

Cyanide is a highly toxic compound that can pose serious health problems to both humans and aquatic organisms. Therefore, the present comparative study focuses on the removal of total cyanide from aqueous solutions by photocatalytic adsorption and degradation methods using ZnTiO3 (ZTO), La/ZnTiO3 (La/ZTO), and Ce/ZnTiO3 (Ce/ZTO). The nanoparticles were synthesized by the sol-gel method and characterized by X-ray powder diffractometry (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Diffuse reflectance spectroscopy (DRS), and Specific surface area (SSA). The adsorption equilibrium data were fitted to the Langmuir and Freundlich isotherm models. Adsorption kinetics were also evaluated using the pseudo-first-order and pseudo-second-order models and the intraparticle diffusion model. Likewise, the photodegradation of cyanide under simulated sunlight was investigated and the reusability of the synthesized nanoparticles for cyanide removal in aqueous systems was determined. The results demonstrated the effectiveness of doping with lanthanum (La) and cerium (Ce) to improve the adsorbent and photocatalytic properties of ZTO. In general, La/ZTO showed the maximum percentage of total cyanide removal (99.0%) followed by Ce/ZTO (97.0%) and ZTO (93.6%). Finally, based on the evidence of this study, a mechanism for the removal of total cyanide from aqueous solutions using the synthesized nanoparticles was proposed.

There is a large worldwide demand for light olefins (C2=–C4=), which are needed for the production of high value-added chemicals and plastics. Light olefins can be produced by petroleum processing, direct/indirect conversion of synthesis gas (CO + H2) and hydrogenation of CO2. Among these methods, catalytic hydrogenation of CO2 is the most recently studied because it could contribute to alleviating CO2 emissions into the atmosphere. However, due to thermodynamic reasons, the design of catalysts for the selective production of light olefins from CO2 presents different challenges. In this regard, the recent progress in the synthesis of nanomaterials with well-controlled morphologies and active phase dispersion has opened new perspectives for the production of light olefins. In this review, recent advances in catalyst design are presented, with emphasis on catalysts operating through the modified Fischer–Tropsch pathway. The advantages and disadvantages of olefin production from CO2 via CO or methanol-mediated reaction routes were analyzed, as well as the prospects for the design of a single catalyst for direct olefin production. Conclusions were drawn on the prospect of a new catalyst design for the production of light olefins from CO2.

The primary function of the skin is that of a physical barrier against the environment and diverse pathogens; therefore, its integrity is essential for survival. Skin regeneration depends on multiple stem cell compartments within the epidermis, which, despite their different transcriptional and proliferative capacity, as well as different anatomical location, fall under the general term of skin stem cells (SSCs). Skin wounds can normally heal without problem; however, some diseases or extensive damage may delay or prevent healing. Non-healing wounds represent a serious and life-threatening scenario that may require advanced therapeutic strategies. In this regard, increased focus has been directed at SSCs and their role in wound healing, although emerging therapeutical approaches are considering the use of other stem cells instead, such as mesenchymal stem cells (MSCs). Given its extensive and broad nature, this review supplies newcomers with an introduction to SSCs, wound healing, and therapeutic strategies for skin regeneration, thus familiarizing the reader with the subject in preparation for future in depth reading.

Pine sawdust steam gasification in a fixed double bed reactor and continuous flow was investigated. K2CO3 as primary catalyst and cobalt supported on γ-Al2O3 and SiO2-Al2O3 as secondary catalyst was investigated. Thermal and catalytic steam gasification was compared. The effect of the support in tar yield and the H2/CO ratio was pursued. It is noteworthy to observe that the primary catalyst increases the biomass gasification. It is also marked the total consumption of CH4 species by the primary catalyst. The catalysts (K2CO3 and K2CO3-Co/γ-Al2O3) reduced tar formation from 11% in the thermal gasification to a value of 2.0% and 0.5% respectively. This tar yield reduction could be explained due to the action of potassium actives species of the primary catalyst combined with the lower acid strength of the support; high metal dispersion of cobalt species and the higher fraction of metallic cobalt species in Co/γ-Al2O3 catalyst. The catalysts decrease the formation of CO2 from 21% in the thermal gasification to values on the order of 3%. The highest H2/CO ratio with a value of 1.6 was obtained by K2CO3-γ-Al2O3 catalytic system. The presence of cobalt supported catalysts favored hydrogen consumption reactions such as reverse water gas shift reaction.

Density functional theory (DFT) studies of the interaction between graphene sheets and nitrile oxides have proved the feasibility of the reaction through 1,3-dipolar cycloaddition. The viability of the approach has been also confirmed experimentally through the cycloaddition of few-layer exfoliated graphene and nitrile oxides containing functional organic groups with different electronic nature. The cycloaddition reaction has been successfully achieved in one-pot from the corresponding oximes under microwave (MW) irradiation. The successful formation of the isoxazoline ring has been confirmed by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS).

La2O3 monolayer catalysts with 90% coverage on Al2O3 and 71% on ZrO2 were successfully obtained by a sol–gel method and the catalytic performance evaluated as fatty acid methyl esters (FAME) production in a canola oil transesterification reaction show differences upon the nature and extent of basic sites. The La2O3 monolayer does not modify strongly the textural properties of the Al2O3 and larger structural changes are detected on ZrO2. For the La2O3-Al2O3 monolayer catalyst, the inter-diffusion Al3+/La3+ cation modify the nature of the acidity and increases the basicity of the Al-O-La species, whereas for the La2O3-ZrO2 monolayer catalyst, appearance of tetragonal ZrO2 structure with larger basicity is detected. The effect of the nature of the support in the catalytic performance in FAME production of the La2O3-ZrO2 and La2O3-Al2O3 monolayer catalyst informed as FAME % (60% at 5 h and 65 °C) for the La2O3-ZrO2 is attributed to the presence of the new medium strength basic sites and the m-ZrO2 structure, whereas the lower basicity of the La2O3-Al2O3 explain the lower fatty acid methyl esters production (45% at 5 h and 65 °C).

Propylene is a very essential building block in the petrochemical industry. There is a fast growing in its demand that is steadily expanding its market. Fluid catalytic cracking units is the second largest propylene source for petrochemical application. FCC units are primarily used in the production of gasoline. However, refiners have taken advantage with the aim of producing and recovering large amounts of propylene from their Fluid catalytic cracking unit by raising the severity of reaction through riser temperature, installation of a propylene recovery unit and addition of a catalyst that is shape selectivity. ZSM-5 is nowadays used as a very efficient fluid catalytic cracking additive for increasing light olefins production i.e. propylene. This short review will be exclusively focused on ZSM-5-containing additives and look at the main strategies used in the design and modifications of ZSM-5 catalysts to increase the propylene production in the FCC units. The review will highlight the most important and the recent modification methods used in enhancing ZSM-5 performance in the FCC process to maximize the yield of light olefins in general, and in particular that of propylene. These methods include particle size and acidity modification, phosphorus treatment, mesoporous/hierarchical structure creation, incorporation alkali metals and some selected transition metals and introduction of rare-earth metal.

The production of methane from the reaction between CO2 and H2 (CO2 methanation) has gained increasing attention in recent years. The rational design of novel catalytic materials for this reaction will depend on the fundamental description of the active sites and the identification of surface reaction intermediates. Currently, there is a debate regarding the mechanism for the CO2 methanation on supported metals, with apparently contradictory proposals suggesting that various surface species could be either reaction intermediates or spectators. Similarly, there is a discussion regarding the nature of the surface sites on the catalysts that activate the CO2 molecule during the reaction. Specifically, it has been suggested that different reaction routes could occur on different metalsupport combinations and on various surface structures. In this manuscript, we critically review the literature on CO2 methanation and discuss the physical evidence that has been presented to propose reaction mechanisms on various supported metals. The relevance of the presence of nanosized metal particles in the catalysts is also discussed.

Hollow carbon spheres (HCSs) were prepared from sugar alcohols encapsulated in UV-cured polymer which were hydrothermally treated in solutions of carbon precursors and carbonised at different temperatures in the presence or absence of graphitisation catalysts (Fe(III) and Ni(II)). The resultant HCSs were then spread at the surface of salt water and submitted to a solar simulator in a special ventilated chamber. The presence of HCSs floating at the surface of water was shown to increase significantly the evaporation rate compared to an HCS-free reference. The effect of carbon precursor, pyrolysis temperature, size and presence of metal was investigated and discussed. The best performances were obtained with nickel-loaded HCSs treated at 1500 °C, leading to a water evaporation rate increased by 70% with respect to the reference. These performances were discussed in terms of floatability, the latter being related to wettability, composition and apparent density of the HCSs. A model was developed for separating the contributions of floatability and thermal conductivity, definitely demonstrating that the former was the key parameter explaining the performances of floating HCSs for evaporating water submitted to a radiant heat flow.

Enhanced bimetallic Rh (0.25, 0.5, 0.75, 1.0 wt%)-Ni 10 wt%) promoted with La2O3(15 wt%) and CeO2(10 wt%)/alumina supported catalysts for ethanol steam reforming compared to their monometallic counterparts is reported. The larger stability of bimetallic Rh-Ni supported catalysts can be due to a: i) cooperative effect of Rh and Ni activities; ii) larger capacity to gasify the methyl group produced from the decomposition of the intermediaries, iii) non-accumulation of acetate species and, iv) favoring the WGS reaction. The 1%Rh-10%Ni bimetallic catalyst shows the best catalytic performance towards H2 selectivity, operating stability over 144 h of reaction and almost non-carbon formation after 24 h on steam. A significant decrease in the carbon-deposition of the 1%Rh-10 wt%Ni bimetallic catalyst, displaying a 70- and 560-times larger stability than their respective monometallic 1%Rh and 10%Ni counterparts was detected. The study of deactivation/regeneration process of the 1%Rh-10%Ni catalytic system indicates that a reactivation treatment fully recovered the catalytic activity of the deactivated catalyst at least in two regeneration cycles. In both cycles, the bimetallic 1%Rh-10%Ni catalyst was stable until 72 h of reaction appearing as a promising catalyst for the reaction of reforming ethanol at mild temperature conditions.

The first carbon aerogels prepared by autocondensation of condensed (flavonoid) tannin, a cheap renewable resource extracted from Mimosa barks, are presented. Mixing aqueous solutions of tannin and sodium silicate indeed produced the very fast gelation of tannins, thus leading to organic hydrogels which were first converted into organic aerogels by supercritical drying, and then into carbon aerogels after pyrolysis at 900 °C. Subsequent dissolution of the silica nanoparticles thus formed within the carbon structure further increased significantly the porosity of the materials. Silica thus appeared to be both the gelation catalyst and a pore-directing agent. In this work, the influence on the porosity of the silica/tannin ratio and of the nature of the etching agent used for removing the silica was thoroughly investigated by combining several techniques. The conditions for producing either the most porous materials or those with the highest surface areas were identified and discussed. Keywords: Condensed tannins, Autocondensation reactions, Mesoporous carbons, Carbon aerogels

Supported rhenium oxide catalysts with different Re loadings (0.5–1.8 Re atom nm−2) and supports (SiO2, γ-Al2O3 and SiO2-Al2O3) were tested for the liquid-phase conversion of furfural at 150–250 °C and 3–5 MPa H2 pressure. The reaction yielded furfural alcohol and 2-methylfuran as main products, the selectivity of which varied significantly with reaction temperature and H2 pressure. The reactivity of reducible rhenium oxide catalysts has been found to be associated with low-valent Re species formed by partial reduction of ReO4− species by reactant hydrogen during the reaction. The formation of these sites is a strong function of the Re loading and the type of support used. In this study, activity based on the mass of the catalyst increased with Re content to a maximum value at 1.4 atoms of Re per nm2 of support but then decreased at higher loading, consistent with loss of active sites due to aggregate formation. The product distribution was invariant to Re loading which is attributed to the nature of the active sites being identical regardless of Re content. In regards to support effect, the activity based on surface Re species increased in the order Al2O3

A series of modified TS-1 catalysts was prepared by post-synthesis hydrothermal treatment of a parent TS-1 zeolite with solutions of different concentrations of tetrapropylammonium hydroxide (TPAOH). The treatment results in an advantageous improvement of the catalytic activity for the liquid oxidation of furfural with H2O2 to produce maleic acid. The highest yield of maleic acid (83%) was obtained when using 0.025 M TPAOH solution; while the maximum yield of the untreated TS-1 was 70%. The catalysts were thoroughly characterised by XRD, UV–Vis, ICP–OES, XPS, TEM, N2-adsorption, DRIFT of chemisorbed deuterated acetonitrile and TEM, in order to elucidate the origin of the catalytic improvement. The characterisation studies allowed us to conclude that, besides the well-known creation of mesopores within the zeolite primary particles, the TPAOH treatment also results in the increase of the hydrophobicity balance of the channels and cavities of the zeolites (via silanols removal). Both properties have a relevant effect on the improvement of the catalytic properties.

The hydridoirida-beta-diketone [(IrH{(PPh2(o-C6H4CO))(2)H})(2)(mu-Cl)][BF4] (2) has been used as a homogeneous catalyst for the methanolysis of ammonia-borane to release up to 3 equivalents of hydrogen in the presence of air. With catalyst loadings as low as 0.2 mol%, ammonia-borane undergoes methanolysis within 6 min at 30 degrees C, with TOF50% of 320 mol(H2) .mol(Ir)(-1).min(-1), or within 80 s at 60 degrees C, with an excellent TOF50% of 1991 mol(H2).mol(Ir)(-1).min(-1), and maintains its catalytic activity in consecutive runs. Triethylamine-borane fails to undergo methanolysis. Kinetic studies indicate first-order dependence on substrate and on catalyst concentration and suggest cleavage of the solvent O-H bond being involved in the rate determining step of the reaction. In methanol solution 2 forms cationic [IrH(MeOH){(PPh2(o-C6H4CO))(2)H}](+) (3) and reacts with Me3N-BH3 to afford a hydridoirida-beta-diketone [IrH(Me3NBH3){(PPh2(o-C6H4CO))(2)H}](+) (4), with the borane adduct eta(1)-coordinated to iridium. Compound [4][BAr4F] shows dynamic behaviour in solution due to exchange of bridging and terminal B-H bonds. A multinuclear NMR study of the catalyzed reaction shows the formation of two ammonia-methoxyborane adduct intermediates, H3N-BH2(OCH3) and H3N-BH(OCH3)(2), and an iridium species proposed of the hydridodiacyl type [IrH(H3NBH3-x(OCH3)(x))(PPh2(o-C6H4CO))(2)] with a coordinated borane adduct. On account of experimental evidence, a simplified catalytic cycle is suggested for the methanolysis of AB to release hydrogen. Partial financial support by Ministerio de Economia y Competitividad MINECO/FEDER (CTQ2015-65268-C2-1-P and PID2019-111281GB-I00), Gobierno Vasco (GIC 18/143 and IT1180-19) Universidad del Pais Vasco (UPV/EHU) and Diputacion Foral de Gipuzkoa are gratefully acknowledged. I. B. acknowledges support by UPV/EHU.

N-Glycosylations are an important post-translational modification of proteins that can significantly impact cell function. Terminal sialic acid in hybrid or complex N-glycans has been shown to be relevant in various types of cancer, but its role in non-malignant cells remains poorly understood. We have previously shown that the motility of human bone marrow derived mesenchymal stromal cells (MSCs) can be modified by altering N-glycoforms. The goal of this study was to determine the role of sialylated N-glycans in MSCs. Here, we show that IFN-gamma or exposure to culture media low in fetal bovine serum (FBS) increases sialylated N-glycans, while PDGF-BB reduces them. These stimuli alter mRNA levels of sialyltransferases such as ST3Gal1, ST6Gal1, or ST3Gal4, suggesting that sialylation of N-glycans is regulated by transcriptional control of sialyltransferases. We next show that 2,4,7,8,9-pentaacetyl-3Fax-Neu5Ac-CO2Me (3F-Neu5Ac) effectively inhibits sialylations in MSCs. Supplementation with 3F-Neu5Ac increases adhesion and migration of MSCs, as assessed by both videomicroscopy and wound/scratch assays. Interestingly, pre-treatment with 3F-Neu5Ac also increases the survival of MSCs in an in vitro ischemia model. We also show that pre-treatment or continuous treatment with 3F-Neu5Ac inhibits both osteogenic and adipogenic differentiation of MSCs. Finally, secretion of key trophic factors by MSCs is variably affected upon exposure to 3F-Neu5Ac. Altogether, our experiments suggest that sialylation of N-glycans is tightly regulated in response to environmental cues and that glycoengineering MSCs to reduce sialylated N-glycans could be beneficial to increase both cell migration and survival, which may positively impact the therapeutic potential of the cells.

Alzheimer’s disease (AD) is a neurodegenerative disease, characterized histopathologically by intra-neuronal tau-related lesions and by the accumulation of amyloid β-peptide (Aβ) in the brain parenchyma and around cerebral blood vessels. According to the vascular hypothesis of AD, an alteration in the neurovascular unit (NVU) could lead to Aβ vascular accumulation and promote neuronal dysfunction, accelerating neurodegeneration and dementia. To date, the effects of insoluble vascular Aβ deposits on the NVU and the blood–brain barrier (BBB) are unknown. In this study, we analyze different Aβ species and their association with the cells that make up the NVU. We evaluated post-mortem AD brain tissue. Multiple immunofluorescence assays were performed against different species of Aβ and the main elements that constitute the NVU. Our results showed that there are insoluble vascular deposits of both full-length and truncated Aβ species. Besides, insoluble aggregates are associated with a decrease in the phenotype of the cellular components that constitute the NVU and with BBB disruption. This approach could help identify new therapeutic targets against key molecules and receptors in the NVU that can prevent the accumulation of vascular fibrillar Aβ in AD.

Food allergy (FA) and, in particular, IgE-mediated cow’s milk allergy is associated with compositional and functional changes of gut microbiota. In this study, we compared the gut microbiota of cow’s milk allergic (CMA) infants with that of cow’s milk sensitized (CMS) infants and Healthy controls. The effect of the intake of a mixture of Bifidobacterium longum subsp. longum BB536, Bifidobacterium breve M-16V and Bifidobacterium longum subsp. infantis M-63 on gut microbiota modulation of CMA infants and probiotic persistence was also investigated. Gut microbiota of CMA infants resulted to be characterized by a dysbiotic status with a prevalence of some bacteria as Haemophilus, Klebsiella, Prevotella, Actinobacillus and Streptococcus. Among the three strains administered, B.longum subsp. infantis colonized the gastrointestinal tract and persisted in the gut microbiota of infants with CMA for 60 days. This colonization was associated with perturbations of the gut microbiota, specifically with the increase of Akkermansia and Ruminococcus. Multi-strain probiotic formulations can be studied for their persistence in the intestine by monitoring specific bacterial probes persistence and exploiting microbiota profiling modulation before the evaluation of their therapeutic effects.

© 2021 by the authors., Dimethyl ether (DME) is a versatile raw material and an interesting alternative fuel that can be produced by the catalytic direct hydrogenation of CO2. Recently, this process has attracted the attention of the industry due to the environmental benefits of CO2 elimination from the atmosphere and its lower operating costs with respect to the classical, two-step synthesis of DME from syngas (CO + H2). However, due to kinetics and thermodynamic limits, the direct use of CO2 as raw material for DME production requires the development of more effective catalysts. In this context, the objective of this review is to present the latest progress achieved in the synthesis of bifunctional/hybrid catalytic systems for the CO2-to-DME process. For catalyst design, this process is challenging because it should combine metal and acid functionalities in the same catalyst, in a correct ratio and with controlled interaction. The metal catalyst is needed for the activation and transformation of the stable CO2 molecules into methanol, whereas the acid catalyst is needed to dehydrate the methanol into DME. Recent developments in the catalyst design have been discussed and analyzed in this review, presenting the different strategies employed for the preparation of novel bifunctional catalysts (physical/mechanical mixing) and hybrid catalysts (co-precipitation, impregnation, etc.) with improved efficiency toward DME formation. Finally, an outline of future prospects for the research and development of efficient bi-functional/hybrid catalytic systems will be presented., The present investigation was performed within the research programs CTQ2016-76505-C3-1 and PID2019-111219RB-100 supported by the Spanish Ministry of Science, Innovation and Universities. The Autonomous Community of Madrid (CAM) is also gratefully acknowledged for funding the BIOTRES-CM (P2018/EMT-4344) project. Elena Millán would like to acknowledge the FPI program from the Spanish Ministry of Science, Innovation and Universities for the research grant.

Catalysts based on zirconia- and alumina-supported tungsten oxides (15 wt % W) with a small loading of platinum (0.3 wt % Pt) were selected to study the influence of the reduction temperature and the nature of the support on the hydroisomerization of n-dodecane. The reduction temperature has a major influence on metal dispersion, which impacts the catalytic activity. In addition, alumina and zirconia supports show different catalytic properties (mainly acid site strength and surface area), which play an important role in the conversion. The NH3-TPD profiles indicate that the acidity in alumina-based catalysts is clearly higher than that in their zirconia counterparts, this acidity can be attributed to a stronger interaction of the WOx species with alumina. The PtW/Al catalyst was found to exhibit the best catalytic performance for the hydroisomerization of n-dodecane based on its higher acidity, which was ascribed to its larger surface area relative to that of its zirconia counterparts. The selectivity for different hydrocarbons (C7&ndash, 10, C11 and i-C12) was very similar for all the catalysts studied, with branched C12 hydrocarbons being the main products obtained (~80%). The temperature of 350 &deg, C was clearly the best reduction temperature for all the catalysts studied in a trickled-bed-mode reactor.

International audience; The gelation of a low value-added industrial waste, phenolic oil (PO), was successfully carried out for the first time in the presence of an acid catalyst and paraformaldehyde (PF), which is a by-product of the formaldehyde industry. Therefore, the use of PO and PF can be considered a win-win situation and as an attempt to valorise these 'wastes' and integrate them into a circular economy. A broad range of formulations has been explored, and the optimal preparation conditions in terms of materials' homogeneity and yield have been identified for gels dried in different ways, leading to xerogels, cryogels and aerogels, as well as to their carbonaceous counterparts after pyrolysis at 900°C. The porous textures of the latter materials were studied in depth, and the results allowed selecting one carbon xerogel for adsorption studies of a reference molecule, methylene blue (MB), in the aqueous phase. Kinetic and equilibrium measurements, as well as the calculation of associated thermodynamic parameters, allowed elucidating the detailed adsorption mechanisms of MB in this type of carbon gel.

Cucurbit[7]uril (CB7) catalyzes the hydrolysis reaction of bis(4-nitrophenyl)carbonate (1) but inhibits that of bis(4-nitrophenyl)thiocarbonate (2). Two relevant CB7 effects are proposed, a base-catalyst mediated by the CB7 portal and an inhibitory role attributed to the lower interaction of the thiocarbonyl group with the solvent in the host cavity, respectively.