Current Catalysis - Volume 3, Issue 2, 2014

Our research Center called “Centro de Investigación y Desarrollo en Ciencias Aplicadas - Dr. Jorge Ronco, CINDECA” celebrated 40 years of its foundation. Our research Institute is devoted to heterogeneous and homogeneous catalysis, reactors design, green chemistry, bio-catalysis, design and synthesis of new catalytic materials between others. In this context, the research topics are oriented towards the technological appl Read More

H3PW12O40 in bulk form presents suitable properties to be used as catalyst in the selective oxidation of sulfides with 35% aqueous hydrogen peroxide, and sulfoxides or sulfones were obtained as products in high to excellent yields and selectivity. We found that sulfides were oxidized to the corresponding sulfoxides, with near stoichiometric 35% w/V aqueous hydrogen peroxide, at room temperature (20°C) and with a catalyti Read More

The commercial biocatalyst Novozym ® 435 was used for the kinetic resolution of (R/S)-ibuprofen through the esterification with short chain alcohols (ethanol, 1-propanol and 2-propanol) in the absence of organic co-solvent. The best enzymatic performance was obtained by employing ethanol as reagent and solvent. Due to the deleterious effect of this alcohol on the integrity of the commercial biocatalyst previously rep Read More

Diphenyilsulfide oxidation by H2O2 as oxidant was studied through the structural effect of the isomorphous W-Mo systems, Anderson type, with [Ni(II)Mo(VI)6-xW(VI)xO24H6]-4 composition. These phases were proved as alternative catalysts instead of W and Mo conventional systems. The characterization of the substituted phases was carried out by different physico-chemical techniques (AAS, DRS, micro-Raman, XRD, TPR) Read More

Dawson-type heteropolyoxometalate compounds (HPC) P2M18O62 -6 (M= Mo, W) have received increasing attention in the catalytic field due to the combination of redox and acidic properties in the same structure. It has been proved that the introduction of vanadium into the Keggin framework is beneficial for redox catalysis, shifting its activity from acid to redox-dominated. In this work we prepared and characterize Read More

This paper presents a rational strategy to purify the lipase B of Candida antarctica of the commercial extract Lipozyme® through size exclusion coupled with anionic exchange chromatography using a non conventional, easy to remove buffer system such as ammonia-ammonium. In this context, each step of the purification was followed through the determination of the protein content, esterase activity measurements, S Read More

Different Fe2O3/Al2O3 catalysts (4 wt% Fe) were prepared and characterized by N2 physisorption, SEM-EDX, TGA and XRD. The systems were tested for the oxidation of high concentration phenol solutions (5 g/L) in a batch reactor at 50 °C, using H2O2 as oxidant. In order to enhance the catalyst stability two strategies were combined: an elevated temperature of calcination (900 °C) and pre-treatments with different orga Read More

Five MnOx-CeO2 samples with a molar ratio Mn-Ce between 0 and 100% were obtained by coprecipitation. The samples, which were called 10/0, 7/3, 5/5, 3/7, 0/10, were characterized by XRD, FTIR, XPS, specific surface area and TPR. Phenol was selected as pollutant. The adsorption of phenol from aqueous solution on Mn-Ce samples was carried out in a batch reactor at 25 and 50° C. The adsorption isotherms were described Read More

MoOx-ZrO2 based catalysts were prepared by equilibrium adsorption in basic (pH 8) or in acid (pH 2) conditions with molybdenum content up to 3 wt.% (pH 8) and up to 8 wt.% (pH 2) using hydrous zirconium oxide, designated as ZrO2(383), as support. The samples were characterized by textural analysis (BET), X-ray diffraction (XRD), Raman and X-ray photoelectron (XPS) spectroscopies. The catalytic behavior was analyz Read More

The catalytic behavior of a series of cobalt catalysts supported on zirconia in the selective catalytic reduction (SCR) of NO has been studied using propane as reducing agent. The catalysts were characterized by Raman Spectroscopy, Temperature Programmed Reduction (TPR), Diffuse Reflectance Spectroscopy UV-Vis (DRS) and X-ray Photoelectron Spectroscopy (XPS) to assess the physicochemical properties of cobalt s Read More

This paper focuses on the preparation, characterization and analysis of the catalytic activity of a series of alumina- supported Cu and Pt catalysts modified with different amounts of cerium, in order to employ them in the carbon monoxide preferential oxidation (CO-PROX) reaction. The catalysts containing only copper as metallic phase allowed us to obtain very good conversion of CO to CO2, reaching a maximum of 70 Read More

The combination of both infrared and Raman spectroscopy are powerful tools to obtain information of catalytic materials at a molecular level. The present investigation shows, a systematic study “in situ” about the effects of the temperature in the molecular structure of the supported phosphotungstic Wells-Dawson heteropolyacid (HPA). The infrared and Raman analyses of the samples were performed under in situ co Read More

In this study, the sulfur tolerance and hydrothermal stability of Cu-KNO3/ZrO2 catalysts in catalytic diesel soot oxidation were investigated. Supported alkaline nitrate catalysts have shown excellent activity for soot oxidation in the presence of O2 or NO/O2. High-temperature water vapor treatments do not affect the catalytic activity, suggesting a good hydrothermal stability of the catalysts. Treatments performed at high S Read More

This paper deals with the computational modeling of the chiral modifier/substrate interaction for chiral modifiers studied in our laboratory, different from those conventionally used in enantioselective hydrogenation reactions. (S)- (+)-1-aminoindane and (R)-(-)-1-aminoindane were chosen as chiral modifiers and the selected substrates were methyl pyruvate, ethyl pyruvate and 1-ethyl-4,4-dimethyl-pyrrolidinae-2,3,5-trione. Th Read More

To understand the complexity of the reactions involved in the steam reforming of glycerol and with the aim of identifying the contribution of C-C and C-O bonds cleavage, in this work we have studied the steam reforming of C3 alcohols simpler than glycerol such as 1-propanol, 2-propanol, 1,2-propanediol and 1,3-propanediol. A Pt/SiO2 catalyst was employed and were studied the conversion and the product distribution for Read More

Various 3-H-1,5-benzodiazepines were prepared from the solvent-free reaction of o-phenylenediamine and substituted 1,3-diphenyl-1,3-propanedione, giving good yields of benzodiazepines. The H6P2W18O62.24H2O solid heteropolyacid, which possesses a Wells-Dawson type structure was used as catalyst both in bulk and silica-supported forms (0.1, 0.2, 0.4 and 0.6 g/g, named 0.1WDSiO2, 0.2WDSiO2, 0.4WDS Read More

The catalytic performance of mesoporous materials with a MCM-41 structure in the reaction of α-pinene oxidation with H2O2 was investigated by a comparative study of Ti-MCM-41and V-MCM-41 catalysts. These materials were prepared by hydrothermal synthesis, from theoretical molar ratios silicon / metal (Si/M) = 20, 60 and 240 in the initial synthesis gel. The results of the catalytic evaluation showed that for a similar molar c Read More

The α-pinene dimerization in liquid phase was studied by using phosphotungstic acid catalysts H3PW12O40, (HPW) supported on commercial silica. These catalysts were characterized by XRD, FT-IR and FT-IR of pyridine adsorbed. Catalyst characterization by XRD showed the presence of HPW crystals on HPWSi catalyst. FT-IR spectra showed only bands assigned to the pyridine adsorption on Bronsted acid sites. The catalytic act Read More

In this paper we propose the preparation of a PtSn bimetallic catalyst through techniques derived from Surface Organometallic Chemistry on Metals (SOMC/M) using water as solvent. The system, PtSn0.2ac, was employed in the chemoselective liquid-phase hydrogenation of acetophenone, cinnamaldehyde and benzaldehyde. The results were compared with those obtained with a PtSn catalyst also prepared via SOMC/M, but Read More