Papers by Carlos Apesteguia
Introduction Zeolites are widely used as catalysts in many industrial processes due to their high... more Introduction Zeolites are widely used as catalysts in many industrial processes due to their high acidity, thermal resistance, and characteristic porous structure. However there are many organic synthesis that still employs strong liquid acids, for example, p-cresol is commercially produced by toluene dehydration with sulfuric acid. The possibility of being able to modify and to control the acid superficial properties, according to the requirements of the reaction to catalyze, is an important challenge in solid catalyst development. The alkylation reactions require high density of strong acid sites, in particular the phenol alkylation with methanol leads to the formation of different product depending on the type of present catalytic sites in the catalyst. Solids containing only strong Brönsted acid sites favor the formation of anisole, whereas those containing both Lewis and Brönsted of strong strength form products of C-alkylation, mainly cresols [1]. The objective of this work wa...
Analytica Chimica Acta, 1990
ABSTRACT A method for the identification and quantification of residues of the antibiotic chloram... more ABSTRACT A method for the identification and quantification of residues of the antibiotic chloramphenicol was developed and validated. The method is based on combined gas chromatography-mass spectrometry with negative-ion chemical ionization and the use of [37Cl2]chloramphenicol as an internal standard. A set of identification criteria, in accordance with guidelines of the European Community, is described. For urine, muscle and eggs limits of detection and quantification of 0.1 μg kg−1 are obtained. The method shows good repeatability and reproducibility. Results for urine were compared with those obtained with a radioimmunochemical procedure and an enzyme immunoassay (Quik-Card). Screening with an immunochemical procedure followed by confirmation with gas chromatography-mass spectrometry was found to be an effective strategy for monitoring residues of chloramphenicol in biological matrices.
Ronaldo Pellegrini, Dec 1, 2008
La cuestión de si es posible desarrollar procesos innovadores en ingeniería catalítica se despren... more La cuestión de si es posible desarrollar procesos innovadores en ingeniería catalítica se desprende de los actuales requerimientos planteados a la producción industrial a nivel mundial. Nuestro grupo viene desarrollando investigaciones en varios campos de la catálisis, que demuestran que, aún en un contexto frecuentemente adverso, nuestro país cuenta todavía con recursos humanos y tecnológicos para lograr este tipo de innovaciones. En este trabajo se detalla el proceso innovador desarrollado para producir sintéticamente mentoles, uno de los productos químicos finos de mayor utilización en las industrias farmacéutica, de cosméticos, pastas dentífricas, golosinas y cigarrillos. Específicamente, se sintetiza mentol con rendimientos mayores al 90% a partir de una nueva materia prima renovable (citral), utilizando un catalizador bifuncional metal/ácido altamente selectivo desarrollado en nuestro laboratorio. Este proceso representa una alternativa tecnológica y económica viable frente a los dos procesos comerciales utilizados actualmente en Japón y Alemania para producir mentol sintético, los cuales parten de materias primas diferentes. La conversión directa de citral a mentoles involucra tres reacciones consecutivas: (1) hidrogenación de E,Z-citral a citronelal; (2) isomerización/ciclización de citronelal a isopulegoles; (3) hidrogenación de isopulegoles a mentoles. Inicialmente, se estudiaron las reacciones (1) y (2) empleando diferentes catalizadores monometálicos y óxidos mixtos ácidos, respectivamente. Ni y Pd fueron los metales más selectivos para la reacción (1), mientras que óxidos mixtos conteniendo sitios ácidos de Lewis y de Brönsted, tales como zeolita Beta y Al-MCM-41, promovieron eficientemente la reacción (2). En base a esos resultados se prepararon tres catalizadores bifuncionales, Pd(1%)/Beta, Ni(3%)/Beta y Ni(3%)/Al-MCM-41, los cuales se evaluaron en la síntesis de mentoles a partir de citral, en una sola etapa. El mejor catalizador fue Ni(3%)/Al-MCM-41, el cual produjo un rendimiento a mentoles de aproximadamente 90% y un 70-75 % de (±)-mentol racémico en la mezcla de mentoles.Fil: Trasarti, Andres Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Marchi, Alberto Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Apesteguia, Carlos Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin
Current Opinion in Green and Sustainable Chemistry, 2018
The metathesis of unsaturated fatty acid methyl esters (FAME) to obtain value-added chemicals is ... more The metathesis of unsaturated fatty acid methyl esters (FAME) to obtain value-added chemicals is becoming increasingly attractive in oleochemistry. Nevertheless, there is a need to develop efficient solid catalysts for FAME metathesis that would allow straightforward catalyst separation and recovery. In this work, the main advances achieved lately using novel heterogeneous catalysts for the homo-metathesis of methyl oleate and the cross-metathesis of methyl oleate with lower olefins are analyzed
Catalysis Today, 2019
The activity, selectivity and stability of carbon-coated Pt(2.0%)/SiO 2 catalysts were investigat... more The activity, selectivity and stability of carbon-coated Pt(2.0%)/SiO 2 catalysts were investigated for producing hydrogen via the APR of xylitol and sorbitol at 498 K and 29.3 bar using polyol(1%)/water feeds in the 0.6 h −1-2.4 h-1 space velocity (WHSV) range. Two carbon-coated samples were prepared by treating with CH 4 at 1173 K for 6 h either SiO 2 (catalyst Pt/SiO 2-C6) or Pt/SiO 2 (catalyst (Pt/SiO 2)-C6). Untreated Pt/SiO 2 and Pt/Al 2 O 3 catalysts were also tested in the polyol APR reaction. Catalytic tests performed during 5 h showed that untreated Pt/SiO 2 was rapidly destroyed on stream whereas the H 2 productivity (mmol H 2 /g cat h) followed the order (Pt/ SiO 2)-C6 > Pt/Al 2 O 3 > Pt/SiO 2-C6. The hydrothermal stability of carbon-coated catalysts was investigated by performing the APR of xylitol for 72 h. Detailed characterization of spent catalysts by different spectroscopic and physical techniques revealed that the surface area, pore structure and Pt crystallite size distribution of the (Pt/ SiO 2)-C6 catalyst were not modified on stream. Results showed that highly hydrothermal stable (Pt/SiO 2)-C6 catalyst was more active and selective than Pt/Al 2 O 3 catalyst for producing hydrogen via the APR of polyols in the WHSV range investigated.
Catalysis Today, 2019
Highlights Catalysts with general formula Ni(12wt.%)-La2(Ce1-xZrx)2O7 (x= 0, 0.5, 1) are very a... more Highlights Catalysts with general formula Ni(12wt.%)-La2(Ce1-xZrx)2O7 (x= 0, 0.5, 1) are very active in the steam and oxidative steam reforming of crude glycerol at 650 °C. NiO and a La2(Ce1-xZrx)2O7 mixed oxide are the unique phases under typical steam reforming conditions. NiLaCeZr also displays the highest stability in steam and oxidative steam reforming tests at 650 °C. Catalyst regeneration can be performed by the removal of carbon and alkali compounds using simple procedures.
International Journal of Hydrogen Energy, 2017
The production of H 2-rich gaseous mixtures from steam reforming of crude glycerol was investigat... more The production of H 2-rich gaseous mixtures from steam reforming of crude glycerol was investigated on ternary NieLaeTi catalysts. NieLaeTi mixed oxides containing 15 wt% of Ni and a La/Ti atomic ratio of 1 were prepared by a coprecipitation method and characterized by a variety of physical and spectroscopic techniques. Samples were calcined in air at 700 C or 850 C for 2 h. NieLaeTi samples calcined at 700 C (NiLaTi700) showed a welldefined NiO phase and an amorphous LaeTi mixed oxide, while those calcined at 850 C (NiLaTi850), exhibited two well defined phases of NiO and LaTiO 3 perovskite, respectively. NiO was completely reduced to metallic Ni on both solids under pure H 2 at 650 C and the resulting Ni 0 phase remained as a separate phase under the steam reforming conditions. Standard catalytic tests for the steam reforming of glycerol were performed at 500 C or 650 C by feeding the fixed-bed tubular reactor with a crude glycerol:water solution containing 30 wt% glycerol. The best results were achieved on NiLaTi700 at 650 C, obtaining H 2 yields and H 2 /CO 2 molar ratios close to the theoretical values predicted by the steam reforming reaction stoichiometry. A slight activity decay was observed on NiLaTi700 with the progress of the reaction, probably reflecting the formation of small amounts of coke.
International Journal of Hydrogen Energy, 2016
The production of hydrogen by aqueous phase reforming (APR) of sorbitol was studied on Pt-based c... more The production of hydrogen by aqueous phase reforming (APR) of sorbitol was studied on Pt-based catalysts at 498 K and 29.3 bar. Four alumina-supported Pt catalysts (0.30, 0.57, 1.50 and 2.77%wt Pt) were prepared. The influence of both the metallic content and the weight hourly space velocity (WHSV, h À1) on sorbitol conversion and hydrogen selectivity, yield and productivity was investigated. Sorbitol conversion and H 2 yield increased with the amount of Pt while the H 2 selectivity in the gas phase did not change significantly. The H 2 productivity was measured on all the catalysts at different WHSV in order to determine the operating conditions required to optimize the production of hydrogen. The H 2 productivity increased with the amount of Pt and went through a maximum as the space velocity was increased. The highest H 2 productivity (22 mmol H 2 /h g cat) was achieved on Pt(2.77%)/Al 2 O 3 at WHSV ¼ 1.8 h À1. At a given space velocity, the H 2 productivity did not depend on the sorbitol concentration in the feed.
Catalysis Science & Technology, 2016
A second-generation Hoveyda–Grubbs complex supported on silica efficiently catalyzes the cross-me... more A second-generation Hoveyda–Grubbs complex supported on silica efficiently catalyzes the cross-metathesis of methyl oleate with ethylene.
Fuel, 2016
h i g h l i g h t s Cu-Mg-Al mixed oxides promote 2-hexanol upgrading to liquid fuels. C9-C24 oxy... more h i g h l i g h t s Cu-Mg-Al mixed oxides promote 2-hexanol upgrading to liquid fuels. C9-C24 oxygenates and hydrocarbons are main products. $70% of the products are C9-C15 compounds for jet fuel applications. Product quality depends on the Cu content. Reaction mechanism changes with the base/metal site ratio.
International Journal of Hydrogen Energy, 2017
The aqueous-phase reforming of xylitol to produce bio-hydrogen was studied on Pt/Al 2 O 3 catalys... more The aqueous-phase reforming of xylitol to produce bio-hydrogen was studied on Pt/Al 2 O 3 catalysts containing 0.30, 0.57, 1.50 and 2.77%wt Pt by varying the weight hourly space velocity (WHSV) between 0.6 and 2.4 h À1. At a constant WHSV value, the gaseous/liquid products ratio depended on the amount of surface Pt concentration on the sample (Pt s). The xylitol conversion to gaseous products increased with Pt s while xylitol conversion to liquid products did not change significantly. At a constant xylitol conversion, the H 2 selectivity increased with Pt s. The H 2 yield increased continuously with both contact time and Pt s. The H 2 productivity (Pr, mmol H 2 /h g cat) increased with both WHSV and Pt s ; indeed, the maximum Pr value obtained when using 1% xylitol in the feed (28 mmol H 2 /g cat h) was obtained on Pt(2.77)/Al 2 O 3 catalysts at WHSV ¼ 2.4 h À1. The effect of the xylitol concentration on H 2 productivity was also investigated. At a constant space velocity, the H 2 selectivity and productivity decreased with increasing xylitol concentration in the feed.
Catalysis Today, 2017
The kinetics of the liquid-phase synthesis of α-, βand γ-ionones from pseudoionone was studied on... more The kinetics of the liquid-phase synthesis of α-, βand γ-ionones from pseudoionone was studied on Brønsted acid solids. Four silica-supported tungstophosphoric acid catalysts containing different heteropolyacid loadings, as well as a silica-supported triflic acid sample and a commercial resin (Amberlyst 35W) were tested in a batch reactor at 343-383 K under autogenous pressure. The final composition of the ionone isomer mixture depended on the catalyst acidic properties and operational conditions. The reaction pathways leading to the three ionone isomers were elucidated by postulating a heterogeneous Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model. First order rate expressions, participation of a single Brønsted acid site in each reaction step and a cationic cyclic intermediate shared by the three ionone isomers were the main model assumptions. It was found that α-, βand γ-ionones form directly from pseudoionone by cyclization. However, the final concentration of αand β-ionones is enhanced in consecutive pathways involving the isomerization of γ-ionone. The relative importance of the isomerization steps and the selective formation of αor β-ionone depend on the Brønsted acid site strength and reaction temperature.
European Journal of Lipid Science and Technology, 2016
The cross-metathesis of methyl oleate with 3-pentenenitrile to obtain 2-undecene, methyl 9-undece... more The cross-metathesis of methyl oleate with 3-pentenenitrile to obtain 2-undecene, methyl 9-undecenoate, methyl 11-cyano-9-undecenoate, and 3-dodecenenitrile was studied at 323 K in a batch reactor using second-generation Hoveyda–Grubbs (HG) catalysts. Self-metathesis of methyl oleate was the main undesired secondary reaction. For a 3-pentenenitrile/methyl oleate reactant ratio (R3PN/MO) of one, the yield (ηC−M) and selectivity (SC−M) to cross-metathesis products were 47 and 63%, respectively. The formation of cross-metathesis products increased with increasing 3-pentene initial concentrations, essentially because the reaction equilibrium was shifted to higher methyl oleate conversions. Thus, ηC−M and SC−M were 74 and 83%, respectively, at R3PN/MO = 5. Nevertheless, the HG complex was significantly deactivated when high R3PN/MO values were employed. Practical applications: Metathesis reactions are becoming increasingly attractive in the oleochemistry industry because they offer novel routes for the valorisation of unsaturated fatty acid methyl esters (FAME) that are cheap feedstocks obtained by transesterification of natural oils and fats. Recently, the cross-metathesis of FAME with functionalized olefins such as esters, allylchlorides, and nitriles has been investigated to obtain renewable α,ω-bifunctional compounds. In particular, the cross metathesis of nitriles with FAME constitutes an attractive synthesis route toward the production of useful polyamide precursors from natural renewable resources. In this work we investigate the cross-metathesis of methyl oleate with 3-pentenenitrile, an internal unsaturated nitrile that does not contain conjugated CC and CN bonds. The results presented in this work show that high yields (74%) and selectivities (88%) to cross-metathesis products are obtained using the second-generation Hoveyda–Grubbs Ru catalyst. The cross-metathesis of methyl oleate with 3-pentenenitrile is studied using the second-generation Hoveyda–Grubbs Ru complex as homogeneous catalyst. High yields (74%) and selectivities (88%) to cross-metathesis products are obtained when pentenenitrile/methyl oleate ratios higher than 3 are employed.
Studies in Surface Science and Catalysis, 2001
Studies in Surface Science and Catalysis, 1998
The synthesis of methanol and isobutanol from synthesis gas over copper-containing Mg y Ce(Y)O x ... more The synthesis of methanol and isobutanol from synthesis gas over copper-containing Mg y Ce(Y)O x catalysts was studied. The influence of the catalyst composition, temperature and contact time on isoalcohol productivity was established. The reaction pathway for isoalcohol synthesis was studied by adding methanol, ethanol or propanol to the reactant feed.
A Global Challenge, 2006
ABSTRACT Argentina is a developing country requiring the sustainable economy growth based in indu... more ABSTRACT Argentina is a developing country requiring the sustainable economy growth based in industrial development for improving the population income. But industrial development may not be conceived without sustainable chemistry, and protection of the environment and the quality of life. Advanced research in catalysis is needed for developing novel clean technologies into chemical design and achieving these economic and environmental goals. In this work, three examples of innovative catalytic processes developed by the Argentinean academic community in the field of renewable resources, clean technologies, and sustainable chemistry are presented. Two examples deal with the use of solid catalysts for the synthesis of fine chemicals.
Studies in surface science and catalysis
Publisher Summary Under industrial conditions, sulfur poisoning of Pt-based naphtha reforming cat... more Publisher Summary Under industrial conditions, sulfur poisoning of Pt-based naphtha reforming catalysts takes place in the presence of a simultaneous deactivation by coke formation. The chapter characterizes the (C + S) deactivation of Pt-based catalysts by employing two monofunctional metallic reactions: benzene hydrogenation, a well known structure insensitive reaction on platinum, and cyclopentane hydrogenolysis, which is a structure sensitive reaction over the same metal. Nevertheless, the main reactions in naphtha reforming proceed via a bifunctional mechanism involving both metallic and acid sites.
International Journal of Hydrogen Energy, 2015
The glycerol steam reforming reaction was studied using Pt-based catalysts in order to selectivel... more The glycerol steam reforming reaction was studied using Pt-based catalysts in order to selectively produce hydrogen. The global steam reforming reaction is the combination of two consecutive steps: i) glycerol decomposition and ii) water gas shift reaction (WGS). Pt supported over solids with markedly different physicochemical properties (SiO 2 , MgO, Al 2 O 3 and TiO 2) were prepared and tested in steam reforming reaction of glycerol (10% wt. aqueous solution) at 573e623 K. Glycerol to gas products conversion of 100% and hydrogen yield of 78.8% were obtained by using Pt over an inert support (Pt/SiO 2 prepared from chlorine-free solution). Acidic supports favored undesirable reactions conducting to liquid products and coke precursors. Furthermore, WGS reaction was studied at reaction conditions compatible with steam reforming over Pt/SiO 2 , Pt/TiO 2 and two catalysts prepared for that purpose: Pt/CeO 2 and Pt/ZrO 2. Pt/TiO 2 showed the highest CO conversion at 623 K. In order to maximize H 2 formation, a double-bed catalytic system (0.5% wt. Pt/ SiO 2 þ 0.5% wt. Pt/TiO 2) was used achieving a 100% hydrogen yield without deactivation on stream.
Acta Crystallographica Section A Foundations of Crystallography, 2009
Lateral growth is observed when the NWR length exceeds the path length of the surface diffusion. ... more Lateral growth is observed when the NWR length exceeds the path length of the surface diffusion. A portion of the diffusing atoms is consumed for lateral growth. This effect leads to the well-known tapering of NWRs. The expected formation of a Cd-rich shell in the buckled region is not found. Hence, the buckling is not due to a lateral growth. Conclusively, only a variation of either the size or shape of the catalyst droplet can cause the buckling. By altering growth parameters like temperature or droplet composition the properties of the liquid droplet are modified. This can cause a different diameter or even an ellipsoidal shape of the droplet leading to an enlarged liquid/solid interface area.
A Global Challenge, Second Edition, 2011
ABSTRACT Argentina is a developing country requiring the sustainable economy growth based in indu... more ABSTRACT Argentina is a developing country requiring the sustainable economy growth based in industrial development for improving the population income. But industrial development may not be conceived without sustainable chemistry, and protection of the environment and the quality of life. Advanced research in catalysis is needed for developing novel clean technologies into chemical design and achieving these economic and environmental goals. In this work, three examples of innovative catalytic processes developed by the Argentinean academic community in the field of renewable resources, clean technologies, and biomass derivatives valorization are presented.
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Papers by Carlos Apesteguia