CATALYTIC PERFORMANCE OF 2D-MXENE NANO-SHEETS FOR THE HYDRODEOXYGENATION (HDO) OF LIGNIN-DERIVED MODEL COMPOUNDS
2D Mxene nano-sheets (Ti3C2Tx) were investigated for the hydrodeoxygenation of guaiacol as a lignin-derived model compound. The catalyst was characterized by TEM, XPS, Raman spectroscopy and TPR. The acid-base properties were measured by TPD-NH3 and TPRe-MeOH. Phenol was the main product obtained, and methylanisole was observed as the second main product…
Elodie Blanco*, Andreas Rosenkranz, Rodrigo Espinoza, Victor M. Fuenzalida, Zhenyu Zhang, Sebastian Suarez, and Nestor Escalona*. Catalytic performance of 2D-Mxene nano-sheets for the hydrodeoxygenation (HDO) of lignin-derived model compounds. Catalysis Communications, (2019) doi.org/10.1016/j.catcom.2019.105833
VALORIZATION OF BIOMASS DERIVATIVES THROUGH THE CONVERSION OF PHENOL OVER SILICA-SUPPORTED MO-RE OXIDE CATALYSTS
Liquid-phase hydrodeoxygenation of phenol over silica-supported MoOx-ReOx catalysts was investigated at 300 °C and 5 MPa of H2. Mixed-oxides catalysts with similar surface metal density (2.3 atoms of metal per nm2 of SiO2) but different relative Mo and Re loadings were prepared by incipient wetness impregnation…
Carla Herrera, Isaac Tyrone, Karen Cruces, Catherine Sepulveda, Lorena Barrientos, Dorothee Laurenti, Christophe Geantet, Ricardo Serpell, David Contreras, Victoria Melin, Nestor Escalona*. Valorization of biomass derivatives through the conversion of phenol over silica-supported Mo-Re oxide catalysts, Fuel 259 (2019) 116245. https://doi.org/10.1016/j.fuel.2019.116245
THE PROMOTER EFFECT OF CO ON THE CATALYTIC ACTIVITY OF THE CU OXIDE ACTIVE PHASE SUPPORTED ON AL2O3 IN THE HYDROGENOLYSIS OF GLYCEROL
The promoting effect of cobalt oxide on alumina-supported Cu oxide catalysts for the hydrogenolysis of glycerol was investigated. A series of Co(y)Cu/Al2O3 oxide catalysts with a fixed Cu loading of 7 wt% and a variable Co loading from 0 to 1.5 wt% was prepared by successive wet impregnation. The catalysts were characterized by X-ray diffraction (XRD), nitrogen sorption, temperature programmed reduction (TPR), ultraviolet-diffuse reflectance spectroscopy (UV-DRS), temperature programmed desorption of ammonia (TPD-NH3), and X-ray photoelectron spectroscopy (XPS)…
C. Sepúlveda*, K. Cruces, J. Gajardo, J. Seguel, R. García, D. Salinas, J. L. G. Fierro, I. T. Ghampson, R. Serpell and N. Escalona. The promoter effect of Co on the catalytic activity of the Cu oxide active phase supported on Al2O3 in the hydrogenolysis of glycerol”. New Journal of Chemistry 43 (2019) 15636-15645. doi.org/10.1039/C9NJ03534F
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…
E.Blanco*, C. Sepulved, K.Cruces, J.L.García-Fierro, N.Escalona*. Conversion of guaiacol over metal carbides supported on activated carbon catalysts” Catalysis Today (2019) doi.org/10.1016/j.cattod.2019.08.029
STRUCTURAL AND INTERFACIAL PROPERTIES OF THE CO2-IN-WATER FOAMS PREPARED T WITH SODIUM DODECYL SULFATE (SDS): A MOLECULAR DYNAMICS SIMULATION STUDY.
Structural characteristics, interfacial distribution and molecular interactions of the components of the CO2(gas)/SDS/water/SDS/CO2(gas) systems as a function of the CO2(gas)/water interface coverage by the SDS surfactant to different amounts of the CO2 were studied with molecular dynamics simulations and the NVT ensemble. We found that the stability of the foams can be improved incrementing of the vapor/water interface coverage with the SDS surfactant and the amount of CO2 in the system.
LG. Parra, J., Domínguez, H., Aray, Y., Izad, P., Zarate, X., Schott, E. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 578, 5 October 2019, 123615.
A detailed analysis of the chemical bonding of the global minimum of icosahedral clusters with formula B10M2 (M = Rh, Ir) revealed that the covalent character between the transition metal and the boron framework as well as the strong delocalization throughout the structure enhances the stabilization of the icosahedral form.
Liang, W., Barroso, J., Jalife, Said, M., Orozco-Ic, Zarate,X., Dong,X. Cui, Z., Merino, G. B10M2 (M = Rh, Ir): finally a stable boron-based icosahedral cluster. Chem. Commun., 2019, 55, 7490.
SYNTHESIS AND CHARACTERIZATION OF 5,10,15,20-TETRAKIS 6 (4-ETHYLPHENYL)PORPHYRIN AND (ZN2 +, MN2 +, SN2 +, NI2 +, AL3 +, 78 V3 +)-DERIVATIVES: PHOTOPHYSICAL AND DFT STUDY
Photophysical study was carried out by UV-Vis and fluorescence spectrophotometry of a novel family of porphyrins of six metallo-derivatives, with the aim of assessing their potential as dye sensitizers for photodynamic therapy (PDT). Computational approaches were employed to analyze the emissive states and to evidence the metal effects on the obtained quantum yield.
Espitia-Almeida, F., Díaz-Uribe, C., Vallejo,W., Gómez-Camargo,D., Romero-Bohorquez, A. R., Schott, E. and Zarate, X. Synthesis and characterization of 5,10,15,20-tetrakis 6 (4-ethylphenyl)porphyrin and (zn2 +, mn2 +, sn2 +, ni2 +, al3 +, 78 v3 +)-derivatives: photophysical and dft study. Chemistry Select 2019, 4, 6290 – 6294.
The hydrogenation of CO2 to methanol is a viable alternative for reducing greenhouse gases net emissions as well as a route for hydrogen storage and transportation. In this context, the synthesis of active and selective catalysts is a relevant objective. In this work, we study the promotion of Pd with Ga and Zn in the hydrogenation of CO2 to methanol at 800 kPa and 220–280 °C. Mono and intermetallic catalysts (Pd/SiO2, PdGa/SiO2 and PdZn/SiO2) were synthesized by incipient wetness impregnation with the aid of triethanolamine as an organic additive, obtaining similar average metal particle sizes (between 9 and 12 nm)…
Manrique, R. , Jiménez, R. Rodríguez-Pereira, J., G. Baldovino-Medrano, V., Karelovic, A.
NOVEL FLUORESCENT SCHIFF BASES AS AL3+ SENSORS WITH HIGH SELECTIVITY AND SENSITIVITY, AND THEIR BIOIMAGING APPLICATIONS
Three new Schiff base chemosensors that exhibited a significant fluorescence enhancement in the presence of Al3+ over other competitive metal ions with a low detection limit, much lower than the WHO acceptable limit (0.05 mg/L or 1.85 μM of Al3+) in drinking water were synthesized. The theoretical research has enabled us to rationalize the turn-on luminescence mechanism of the reported systems. Finally, one chemosensor showed good solubility and compatibility with and without Al3+ and some fluorescent bioimaging in human epithelial cells Hs27 are reported.
Berrones-Reyes, J., M. Muñoz-Flores, B., Gómez-Treviño, A., A. Treto-Suárez, M., Páez-Hernández, D., Schott, E., Ximena Zarate, X., M. Jiménez-Pérez, V. Novel fluorescent Schiff bases as Al3+ sensors with high selectivity and sensitivity, and their bioimaging applications. Materials Chemistry and Physics 2019, 233, 89-101.
LANTHANUM OXIDE BEHAVIOR IN LA2O3-AL2O3 AND LA2O3-ZRO2 CATALYSTS WITH APPLICATION IN FAME PRODUCTION
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…
Salinas, D., Escalona, N., Pecchi, G. Fierro, L.G. Lanthanum oxide behavior in la2o3-al2o3 and la2o3-zro2 catalysts with application in fame production. Fuel, 2019, 253, 400-408.
UNDERSTANDING THE AROMATICITY OF C6X6 (X = H, F, CL, BR, I). INSIGHTS FROM DIFFERENT THEORETICAL CRITERIA
Different theoretical methodologies were applied to a series of substituted benzenes C6X6 (with X = H, F, Cl, Br and I) to pursue the property of aromaticity. HOMA (as structural criterion), NICS (FIPC-NICS, isotropic and ZZ employed as magnetic criteria) as well as the indexes ASE, MCI, PDI and FLU, interestingly provided controversial data respect to the magnetically induced current density plots and chemical intuition, which is extensively discussed in the herein work…
Zarate, X., MacLeod-Carey, D., Muñoz-Castro, A., Schott, E. Understanding the aromaticity of C6X6 (X = H, F, Cl, Br, I). Insights from different theoretical criteria. Chemical Physics Letters, 2019, 720, 52-57.
BEHAVIOR OF THE SDS/1-BUTANOL AND SDS/2-BUTANOL MIXTURES AT THE WATER/N- OCTANE INTERFACE THROUGH MOLECULAR DYNAMICS SIMULATIONS
Interfacial properties of water/SDS+1-butanol/n-octane and water/SDS+2-butanol/n-octane systems have been determined using MD simulations with the aim of studying the molecular interactions between alcohols and SDS when are located at the water/n-octane interface. Also, interfacial properties of water/1-butanol/n-octane, water/2-butanol/n-octane and water/SDS/n-octane systems were determined to validate the used force fields…
Parra, J. G., Aray, Y.R,Iza, P., Zarate, X., Schott. Behavior of the SDS/1-butanol and SDS/2-butanol mixtures at the water/n-octane interface through molecular dynamics simulations. E. Chemical Physics 2019, 523, 138-149.
EFFECT OF PARTICLE SIZE ON THE PHOTOCATALYTIC ACTIVITY OF MODIFIED RUTILE SAND (TIO2) FOR THE DISCOLORATION OF METHYLENE BLUE IN WATER
The advanced oxidation process (AOP) has been identified as a promising technology for pollutant degradation. To maximize the performance of this process, new materials need to be found or existing materials need to be modified. In this work, the effect of the particle size of modified rutile materials on the photocatalytic discoloration of methylene blue was investigated. Rutile samples with different particle sizes were obtained by milling, and the photocatalytic reaction was carried out in a continuous magnetic stirring photoreactor under UV–vis illumination…
Retamoso, C, Escalona, N., González, M., Barrientos, L., Allende-González, P., Stancovich, R., Serpell, R., Fierro, J.L.G., López, M. Journal of Photochemistry and Photobiology A: Chemistry 2019, 378, 136-141.
ENHANCED BIMETALLIC RH-NI SUPPORTED CATALYSTS ON ALUMINA DOPED WITH T MIXED LANTHANUM-CERIUM OXIDES FOR ETHANOL STEAM REFORMING
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…
Campos, C.H., Pecchi, G., Fierro, J. L. G., Osorio-Vargas, P. Enhanced bimetallic rh-ni supported catalysts on alumina doped with t mixed lanthanum-cerium oxides for ethanol steam reforming. Molecular Catalysis 2019, 469, 87-97.
VISIBLE LIGHT ASSISTED PHOTODEGRADATION OF THIMEROSAL BY HIGH PERFORMANCE T ZNFE2O4/POLY(O-PHENYLENEDIAMINE) COMPOSITE
Thimerosal is a mercury-based preservative that is used in pharmaceuticals, vaccines and health-care products. However, thimerosal toxicity has been well explored and hence it should be properly treated for avoiding its occurrence in the environment…
Sandoval, C., Ranganathan, S., Ramírez, E., Mansilla, H.D., Dinamarca, R., Pecchi, G., Yáñez, J. Visible light assisted photodegradation of thimerosal by high performance t znfe2o4/poly(o-phenylenediamine) composite. Materials Research Bulletin 2019, 116, 8-15.
SELECTIVE OXIDATION OF CYCLOHEXANE TO CYCLOHEXANOL BY BIOI UNDER VISIBLE T LIGHT: ROLE OF THE RATIO (1 1 0)/(0 0 1) FACET
The development of semiconductors capable of photocatalytic activity under visible light is very important, because such materials are potentially useful for performing photocatalytic conversion under solar illumination…
Contreras, D., Melin, V., Márquez, K., Pérez-González, G., Mansilla, H. D., Pecchi, G., Henríquez, A. Selective oxidation of cyclohexane to cyclohexanol by bioi under visible t light: role of the ratio (1 1 0)/(0 0 1) facet. Applied Catalysis B: Environmental 2019, 251, 17-24.
Carbon-containing SiO2-based photocatalysts were prepared by the solvothermal treatment of rice husk as biogenic precursor in the presence and absence of TiO2 and used for the photocatalytic degradation of rhodamine-B under simulated solar light. Data showed that the prepared catalysts are mainly composed of biogenic silica and displayed mesoporous character with surface areas ranging from 65 to 174 m2 g-1…
Fernández de Cordoba, M. C., Matos, J., Montaña, R., Poon, S. P., Lanfredi, S., Praxedes, F. R., Hernández-Garridoe, J.C., Calvino, J.J. Rodríguez-Aguado, E., Rodríguez-Castellón, E., Aniab, C.O. Sunlight photoactivity of rice husks-derived biogenic silica. Catalysis Today 2019, 328, 125-135.
C-DOPED ANATASE TIO2: ADSORPTION KINETICS AND PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE AND PHENOL, AND CORRELATIONS WITH DFT ESTIMATIONS
This work shows an easy and eco-friendly methodology to obtain almost pristine anatase phase of TiO2 by using furfural, a biomass-derived molecule, as a bio-template. The photocatalytic activity was studied following the degradation of methylene blue and phenol under artificial solar irradiation. Results were compared against those obtained on a commercial pristine anatase TiO2…
Matos, J., Ocares-Riquelme, J., Poon, P.S., Montaña, R., García, X., Campos, K., Hernández-Garrido, J.C. Titirici, M. M. C-doped anatase TiO2: Adsorption kinetics and photocatalytic degradation of methylene blue and phenol, and correlations with DFT estimations. Journal of Colloid and Interface Science 2019, 547, 14-29.
MAGNETIC FE2O3–SIO2–MEO2–PT (ME = TI, SN, CE) AS CATALYSTS FOR THE SELECTIVE HYDROGENATION OF CINNAMALDEHYDE. EFFECT OF THE NATURE OF THE METAL OXIDE
The type of metal oxide affects the activity and selectivity of Fe2O3–SiO2–MeO2–Pt (Me = Ti, Sn, Ce) catalysts on the hydrogenation of cinnamaldehyde. The double shell structure design is thought to protect the magnetic Fe2O3 cores, and also act as a platform for depositing a second shell of TiO2, SnO2 or CeO2 metal oxide…
Dinamarca, R.; Espinoza-González, R.; Campos, C.H.; Pecchi, G. Magnetic Fe2O3–SiO2–MeO2–Pt (Me = Ti, Sn, Ce) as Catalysts for the Selective Hydrogenation of Cinnamaldehyde. Effect of the Nature of the Metal Oxide. Materials 2019, 12, 413.
EFFECT OF RE CONTENT AND SUPPORT IN THE LIQUID PHASE CONVERSION OF FURFURAL TO FURFURYL ALCOHOL AND 2-METHYL FURAN OVER REOX CATALYSTS
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…
Toledo, F., Ghampson, I.T., Sepúlveda, C., García, R., Fierro, J.L.G., Videla, A., Serpell, R., Escalona, N. Effect of Re content and support in the liquid phase conversion of furfural to furfuryl alcohol and 2-methyl furan over ReOx catalysts. Fuel 2019, 242, 532-544.
A well-characterized Re-MoO x /TiO 2 catalyst was used to investigate the reaction sequence involved during the hydrodeoxygenation of anisole in a batch reactor by varying the initial anisole concentration in the reactant mixture (0.182–0.382 mol L −1 corresponding to 2.6–5.4 wt.%), the reaction temperature (250–325 °C) and hydrogen pressure (30–60 bar)…
Ghampson, T., Canales, R., Escalona, N. “A study of hydrodeoxygenation of anisole over Re-MeOx/TiO 2 catalyst”. Applied Cataysis A, General, 2018, 549, 225-236.
The hydrodeoxygenation of anisole at 300 °C and 3 MPa H 2 in a batch reactor is used as a model reaction to explore the performance of TiO 2 -supported Re-MoO x and Re-VO x catalysts. The binary catalysts were prepared with different Re and MoO x (or VO x ) loadings and characterized by nitrogen physisorption, ICP-MS and AAS, XRD, FTIR, H 2 -TPR, NH 3 – TPD, H 2 -TPD, TEM and XPS techniques…
Ghampson, I.T., Pecchi, G., Fierro, J.L.G., Videla, A., Escalona, N. “Catalytic hydrodeoxygenation of anisole over ReMoOx/TiO 2 and Re-Vox/TiO 2 catalysts” Applied Catalysis B: Enviromental 208 (2017) 60-74.