Special Issue "Catalysis for Global Development. Contributions around the Iberoamerican Federation of Catalysis"

A special issue of Catalysts (ISSN 2073-4344).

Deadline for manuscript submissions: 31 January 2019

Special Issue Editors

Guest Editor
Prof. Dr. Helder T. Gomes

Laboratory of Separation and Reaction Engineering – Laboratory of Catalysis and Materials (LSRE-LCM Associate Laboratory), Polytechnique Institute of Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal
Website | E-Mail
Phone: +351 273 303 110
Interests: heterogeneous catalysis; magnetic nanocatalysts; carbon-based materials; design, preparation and characterization of catalysts; advanced oxidation processes; environmental catalysis; catalytic wet peroxide oxidation; valorisation of sub-products; chemical engineering
Guest Editor
Prof. Joaquim Luís Faria

Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (Associate Laboratory LSRE-LCM), Department of Chemical Engineering, Faculdade de Engenharia da Universidade do Porto (FEUP), Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
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Phone: +351 220 413 683
Fax: +351 225 081 449
Interests: catalysis and photocatalysis; physical-organic chemistry; chemistry and materials science; spectroscopic techniques; fine chemical synthesis; advanced oxidation processes; solar fuels; nanotechnology and nanoscience; biophysics and biochemistry; chemical education and science communication; chemical engineering

Special Issue Information

Dear Colleagues,

Following the biennial meetings, held since 1968, the Iberoamerican Federation of Catalysis Societies (FISoCat), the Portuguese Chemical Society (SPQ) and the University of Coimbra jointly organizes the XXVI Iberoamerican Congress on Catalysis (CICat 2018), between the 9th and 14th of September 2018, in Coimbra, Portugal. CICat 2018 is of particular historical importance, as it marks the 50th anniversary of the beginning of this series of meetings. The present Special Issue will feature the works presented at CICat 2018 and also additional contributions, that promote linkage of the catalytic science, technology, education and culture plans and processes, involved in cooperation programs and projects among the Iberoamerican Member States and of these with the states and institutions of other regions.

Authors with expertise in any topic of catalysis are cordially invited to submit their manuscripts to this Special Issue of Catalysts. Significant full papers and review articles are very welcome. The topics of the conference will cover various aspects of catalysis in all of its diversity, as well other areas on the boundaries such as environmental protection, energy, sustainability, nanoscience, fine chemistry, biotechnology, surface chemistry and cultural heritage.

Prof. Dr. Helder Gomes
Prof. Dr. Joaquim Luís Faria
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Catalysts is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Environmental Catalysis
  • Industrial Catalysis, Oil Refining, Natural Gas Conversion and Petrochemistry
  • Design, Preparation and Characterization of Catalysts
  • Sustainable Processes and Clean Energies
  • Fine Chemistry
  • Biocatalysis
  • Homogeneous Catalysis
  • Heterogeneous Catalysis
  • Photocatalysis

Published Papers (3 papers)

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Research

Open AccessArticle Synthesis, Performance and Emission Quality Assessment of Ecodiesel from Castor Oil in Diesel/Biofuel/Alcohol Triple Blends in a Diesel Engine
Catalysts 2019, 9(1), 40; https://doi.org/10.3390/catal9010040
Received: 13 November 2018 / Revised: 17 December 2018 / Accepted: 20 December 2018 / Published: 3 January 2019
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Abstract
This research aims to promote the use of second-generation biofuels based mainly on Castor oil, which is not adequate for food use, and Sunflower oil as a standard reference for recycled oils. They have been applied in the production of Ecodiesel, a biofuel
[...] Read more.
This research aims to promote the use of second-generation biofuels based mainly on Castor oil, which is not adequate for food use, and Sunflower oil as a standard reference for recycled oils. They have been applied in the production of Ecodiesel, a biofuel that integrates glycerol as monoglyceride, employing sodium methoxide as homogeneous catalyst and ethanol as solvent, but operating in milder conditions than in the synthesis of conventional biodiesel in order to obtain a kinetic control of the selective transesterification. The behavior of biofuels has been evaluated in a conventional diesel engine, operating as an electricity generator. The contamination degree was also evaluated from the opacity values of the generated smokes. The different biofuels here studied have practically no differences in the behavior with respect to the power generated, although a small increase in the fuel consumption was obtained in some cases. However, with the biofuels employed, a significant reduction, up to 40%, in the emission of pollutants is obtained, mainly with the blend diesel/castor oil/alcohol. Besides, it is found that pure Castor oil can be employed directly as biofuel in triple blends diesel/biofuel/alcohol, exhibiting results that are very close to those obtained using biodiesel or Ecodiesel. Full article
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Open AccessFeature PaperArticle A New Tool in the Quest for Biocompatible Phthalocyanines: Palladium Catalyzed Aminocarbonylation for Amide Substituted Phthalonitriles and Illustrative Phthalocyanines Thereof
Catalysts 2018, 8(10), 480; https://doi.org/10.3390/catal8100480
Received: 1 October 2018 / Revised: 16 October 2018 / Accepted: 17 October 2018 / Published: 20 October 2018
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Abstract
The amide peptide bond type linkage is one of the most natural conjugations available, present in many biological synthons and pharmaceutical drugs. Hence, aiming the direct conjugation of potentially biologically active compounds to phthalocyanines, herein we disclose a new strategy for direct modulation
[...] Read more.
The amide peptide bond type linkage is one of the most natural conjugations available, present in many biological synthons and pharmaceutical drugs. Hence, aiming the direct conjugation of potentially biologically active compounds to phthalocyanines, herein we disclose a new strategy for direct modulation of phthalonitriles, inspired by an attractive synthetic strategy for the preparation of carboxamides based on palladium-catalyzed aminocarbonylation of aryl halides in the presence of carbon monoxide (CO) which, to our knowledge, has never been used to prepare amide-substituted phthalonitriles, the natural precursors for the synthesis of phthalocyanines. Some examples of phthalocyanines prepared thereof are also reported, along with their full spectroscopic characterization and photophysical properties initial assessment. Full article
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Graphical abstract

Open AccessArticle Synthesis and Regeneration of Nickel-Based Catalysts for Hydrodeoxygenation of Beech Wood Fast Pyrolysis Bio-Oil
Catalysts 2018, 8(10), 449; https://doi.org/10.3390/catal8100449
Received: 17 August 2018 / Revised: 29 September 2018 / Accepted: 8 October 2018 / Published: 12 October 2018
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Abstract
Four nickel-based catalysts are synthesized by wet impregnation and evaluated for the hydrotreatment/hydrodeoxygenation of beech wood fast-pyrolysis bio-oil. Parameters such as elemental analysis, pH value, and water content, as well as the heating value of the upgraded bio-oils are considered for the evaluation
[...] Read more.
Four nickel-based catalysts are synthesized by wet impregnation and evaluated for the hydrotreatment/hydrodeoxygenation of beech wood fast-pyrolysis bio-oil. Parameters such as elemental analysis, pH value, and water content, as well as the heating value of the upgraded bio-oils are considered for the evaluation of the catalysts’ activity and catalyst reuse in cycles of hydrodeoxygenation after regeneration. The reduction temperature, selectivity and hydrogen consumption are distinct among them, although all catalysts tested produce upgraded bio-oils with reduced oxygen concentration, lower water content and higher energy density. Ni/SiO2, in particular, can remove more than 50% of the oxygen content and reduce the water content by more than 80%, with low coke and gas formation. The evaluation over four consecutive hydrotreatment reactions and catalyst regeneration shows a slightly reduced hydrodeoxygenation activity of Ni/SiO2, mainly due to deactivation caused by sintering and adsorption of poisoning substances, such as sulfur. Following the fourth catalyst reuse, the upgraded bio-oil shows 43% less oxygen in comparison to the feedstock and properties comparable to the upgraded bio-oil obtained with the fresh catalyst. Hence, nickel-based catalysts are promising for improving hardwood fast-pyrolysis bio-oil properties, especially monometallic nickel catalysts supported on silica. Full article
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Graphical abstract

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Dibenzothiophene Hydrodesulfurization over P-como on Sol-gel Alumina Modified by La Addition Effect of Rare Earth Content
Authors: J. Escobar*, M.C. Barrera, D.A. Solís-Casados, V. Santes, J. Sánchez-Valente and J.E. Terrazas
Affiliation: Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas 152, San Bartolo. Atepehuacan, Gustavo A. Madero, D.F., México
Correspondence: [email protected]

Title: NOx Photocatalytic Degradation on Self-cleaning TiO2-GO Coatings: Influence of Support
Authors: Marisol Faraldos 1,*, Gema Luna-Sanguino 1, Álvaro Tolosana-Moranchel 2, Qingxu Jin 3, Kimberly E. Kurtis 4 and Ana Bahamonde 1
Affiliation: 1 Instituto de Catálisis y Petroleoquímica, ICP-CSIC, Madrid, Spain; 2 Sec. Ingeniería Química. Fac. Ciencias. UAM. Madrid, Spain; 3 School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, USA
Correspondence: [email protected]
Abstract: This study analyzes the effect of the incorporation of graphene oxide (GO) on the behavior of a photocatalytic coating based on TiO2, when applied to ceramic and cementitious supports, as a solution to abate atmospheric pollution in urban areas.  To this end, a titanium dioxide nanoparticle composite with 2% graphene oxide has been synthetized with the aim to extend the harvesting of solar radiation spectrum. The coating has been applied by spray with a theoretical thickness of approximately 12 μm, in order to present a sustainable an economically viable alternative. All the applied coatings improved the self-cleaning performance and their decontaminating capacity when irradiated. The composition of support played an important role in both the kinetics and the efficiency of both processes, so the interaction between support-coating has been studied by adhesion tests, wettability and surface morphology. The incorporation of GO resulted in an improvement of the efficiency and kinetics of the Methylene Blue photodegradation on the supports with ceramic components that was not observed in the case of cementitious supports. The same behavior was also observed in the photocatalytic degradation of NOx.

Title: Effect of Cerium Precursor in the Synthesis of Ce-MCM-41 and in the Efficiency for Liquid-Phase Oxidation of Benzyl Alcohol
Authors:
Carlos Martins Aiube and Julio Lemos de Macedo
Affiliation: Group of New Materials for Sustainable Chemical Catalysis, Instituto de Química, Campus Darcy Ribeiro, Universidade de Brasília, 70910-900, Brasília, Brazil
Correspondence: [email protected] (C.M.A.); [email protected] (J.L.M.)
Abstract: Understanding the effects of synthetic parameters in the catalytic activity of heterogeneous catalysts is of utmost importance when aiming optimal reaction conditions. Hence, we disclose in this work the synthesis, characterization and efficiency of samples of cerium-modified MCM-41 (Si/Ce ratio = 25) in the liquid-phase oxidation of benzyl alcohol, observing, for the first time, differences in catalytic activity when using different cerium synthetic precursors: CeCl3·6H2O and Ce(NO3)3·6H2O (Ce-MCM-Cl and Ce-MCM-NO3, respectively). The heteroelement is in the form of species highly dispersed in the material with 4+ oxidation state and mainly in tetrahedral coordination, according to UV-Vis-DRS and FTIR data. XRD data shows that incorporation leads to the expansion of the unit cell and partial loss of the typical hexagonal mesophase of MCM-41 in both materials. Nonetheless, the emergence of microstructural differences of both materials due to the metal-precursor was observed by several techniques. In the oxidation of benzyl alcohol, the Ce-MCM-Cl sample had higher activity in most of the tested conditions, whereas the Ce-MCM-NO3 sample was more selective towards benzaldehyde. This effect observed in the catalytic behavior shows the importance of choosing ideal heteroelement precursors in obtaining materials with desirable final properties.

Title: Pd Nanoparticles on Mixed Metal Oxides for the Synthesis of Piperazines from Acetol
Authors:
Jaime Mazarío, Zaher Raad and Marcelo E. Domine *
Affiliation: Instituto de Tecnología Química (UPV-CSIC), Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas, Avda. de los Naranjos s/n, 46022 Valencia, Spain
Correspondence: [email protected]
Abstract: A novel process for the synthesis of high-valued nitrogen-compounds from biomass derived platform chemicals by using sustainable heterogeneous catalysts is here studied. Particularly, the work is focused on the use of hydroxyacetone (or acetol, product of the selective dehydration of glycerol) as a carbon source to produce piperazines. The piperazine ring is an anthelmintic and can be also found as structural unit of many drugs (i.e. antihistamines, antidepressants, etc.), thereby being an interesting intermediate in organic synthesis, as well as used in CO2 scavenging. In order to obtain the desired 2-methylpiperazine (2-MP), a reductive amination of acetol with ethylenediamine is considered. The study intends to develop and optimize the best possible catalyst for this reaction, by always working under mild reaction conditions. Based in previous works, Pd nanoparticles supported on simple (i.e. TiO2, Al2O3, ZrO2 and MgO) and mixed metallic oxides (i.e. TiO2-Al2O3, TiO2-ZrO2 and ZrO2-Al2O3, prepared in ammonia) were prepared, characterized by different analytical techniques (i.e. ICP analysis, NH3-TPD, TPR, XRD and HR-TEM), and used as catalysts to perform the reductive amination to yield the desired piperazine. The best results were attained with Pd/TiO2-Al2O3 and Pd/ZrO2-Al2O3 catalysts, with 2-MP yields higher than 80%, in correlation with the improvement in textural properties observed for those mixed oxides-based materials. These results have also been confirmed when working with much lower catalyst loadings, and even after several catalytic re-uses, main trends observed being explained according to the enhanced physicochemical properties of the selected materials. This work opens up a new catalytic route for taking advantage of acetol, but also offers new insights and efficient catalysts to obtain nitrogenated compounds from different bio-based raw materials.

Title: Improve of Catalytic Bioethanol Conversion in Li-exchanged Na-Y, Na-X and K-L Zeolites
Author:
Jesús Álvarez-Rodríguez
Affiliation: Dpto. Química Inorgánica y Química Técnica, Facultad de Ciencias.UNED, C/ Senda del Rey, 9, 28040-Madrid España
Correspondence: [email protected]
Abstract: The effect of the zeolite type (Na-X, Na-Y and K-L) and that of lithium exchanged in the zeolites framework on the catalytic activity is studied for the chemical revalorisation of bioethanol, by either dehydration or dehydrogenation reactions in the gas phase, at atmosphere pressure under helium flow. It is reported as the catalytic activity of the zeolites depends on the Si/Al ratio, in manner that the higher the ratio the lower the activity, ethylene being the main reaction product for all the original zeolites. For the lithium exchanged samples the catalytic activity is improved in all them. In contrast, selectivity towards ethylene and diethyl-ether decrease while that of acetaldehyde is enhanced. These behaviours are discussed from the characterization results obtained by chemical analysis ICP-OES, X-ray diffraction (XRD) and thermal programmed desorption of chemisorbed CO2 (TPD-CO2).

Title: Base Hybrid Catalysts for the Formation of C–C Bonds
Authors:
M.C. Hernández-Soto, A. Erigoni, U. Díaz, F. Rey, C. Segarra *
Affiliation: Instituto de Tecnología Química (ITQ), Avenida de los Naranjos s/n46022, Valencia, España
Correspondence: [email protected]
Abstract: New base hybrid catalysts, based on silyl-derivatives of organic molecules carrying amino, diamino, pyrrolidine, ammonium, pyrazolium and imidazolium functionalities have been successfully achieved through post synthetic grafting onto MCM-41 support. Different characterization techniques were implemented to study the properties of the materials, such as nuclear magnetic resonance (NMR), elemental analysis and N2 physisorption analysis. The catalytic activity and recyclability of these compounds as base catalysts was demonstrated for C–C bond forming reactions such as Knowevenagel condensations and Michael additions.

Title: Al2O3-Ga2O3 Oxides Doped with Silver Oxide Prepared by Sol-gel Method. Photocatalytic Degradation of Diclofenac
Authors:
J. E. Casillas García a, C. Velásquez b, F. Tzompantzi c, J. A. López Gaona c and A. Barrera Rodríguez a
Affiliation: a Centro Universitario de la Ciénega, Universidad de Guadalajara, México; b Centro Universitario de los Valles, Universidad de Guadalajara, México; c Depto. de Química, UAM-Iztapalapa, México
Correspondence: [email protected]
Abstract: Degradation of diclofenac, a widely used anti-inflammatory drug which has been found as contaminat in wastewater, has been carried out by photo catalytic methods on Al2O3-Ga2O3 oxides doped with Ag2O. The Al-Ga-Ag oxides were prepared by sol-gel method and characterized by N2 physical adsorption, XRD, SEM, TEM, UV-Vis, Fluorescence and Raman spectroscopy. Photocatalytic activity test in the degradation of diclofenac was carried out using a batch-type reactor under UV irradiation source (λ = 254 nm). Al2O3 showed specific surface areas (SBET) of 332.0 m2 g-1, and decreased when Ga2O3 and Ag2O were added. XRD patterns only showed diffraction peaks corresponding to γ-Al2O3. No other diffraction peaks were observed, suggesting that small particles of Ga2O3 and Ag2O are highly dispersed within the γ-Al2O3 bulk. Raman spectra only showed shift bands at 500 and 2440 cm-1, which correspond to Al-O and Al-OH vibration modes. Intensity of fluorescence spectra of excited materials at 271 nm, which is related to charge carrier recombination rate, was lower for Ag2O doped Al2O3-Ga2O3 than that of Al2O3 alone. The photocatalytic activity showed that after 30 minutes Al2O3 photoconverts 79 % of diclofenaco and 88 % when Ga2O3 is incorporated. Furthermore, when Al-Ga oxide is Ag doped, photoconversion increased up to 96.0 %. Mineralization was about 80 %.

Title: Screening of the catalytic conditions for the boronic esters synthesis in the presence of layered double hydroxides
Author:
Luiz Fernando Malta
Affiliation: Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária CT Bloco A-641, Rio de Janeiro 21945-970, RJ, Brazil
Correspondence: [email protected]
Abstract: Organic derivatives of boron such as arylboronic esters and acids are important precursors for a wide range of environmental, energy and health applications. Several catalytic methods for their synthesis involve the use of sensitive organometallic precursors along with the presence of structurally complex ligands. Recent methods, however, indicates a possible role of Cu catalytic systems towards a more convenient approach. Herein, we demonstrate preliminary studies envisaging the synthesis of pinacol-derived arylboronic esters from a catalytic system based on Cu/Al layered double hydroxides (LDH). The Cu/ Al LDH was initially prepared according to the co-precipitation method previously reported but results pointed to the presence of malachite as a second phase. Since this is not catalytically active, improvements in the LDH preparation route led to a low level of malachite, according to results from Rietveld refinement. Preliminary catalytic results in the presence of Cu/ Al LDH and Pd(II) precursor pointed to a high aryl halide conversion in the reaction with bis(pinacolate)diboron, suggesting a possible synergic effect between copper and palladium. Indeed, initial reaction scope showed a positive influence of electron-withdrawing groups in the aromatic ring. By considering their low cost and good catalytic activity, the present catalytic system can be an alternative to the use of Pd phosphine complexes in borylation reactions.

Title: Improved Etherification of Glycerol by tert-butyl Alcohol by the Addition of Dibutil Eter as Solvent
Author:
Carmen María Domínguez Torre
Affiliation: Chemical Engineering and Materials Department, Universidad Complutense de Madrid, Spain
Correspondence: [email protected]
Abstract: The etherification of glycerol with terbutanol in the presence of acid catalysts gives rise to the production of ethers (monoethers, diethers and triethers) of high added value, which are used as additives in fuels. This reaction is limited by the equilibrium, which can be modified by the addition of solvents that selectively solubilize the products of interest along with terbutanol. In this work, it has been demonstrated that the introduction of dibutyl ether into the reaction system allows shifting the reaction equilibrium, increasing the production of diethers. From the study of the main operating conditions, it was determined that the concentration of solvent has a positive effect on the selectivity towards the products of interest whereas the concentration of the catalyst (ion exchange resin, A15) and the reaction temperature are determinant. On the other hand, working with concentrations of terbutanol above the stoichiometric one, does not report great advantages. Thus, the optimal operating conditions to maximize the conversion of glycerol and the selectivity towards diethers are 70 ° C, 20% catalyst, the stoichiometric ratio of terbutanol (G:TB = 1:3) and 1:2 molar ratio of dibutyl ether:terbutanol. A study of three consecutive reaction cycles showed the high stability of the catalyst, obtaining identical results.

Title: Evaluation of Synthesis Parameters in the Zeolite ZSM-12 (MTW) Using Inorganic Structure Compensation
Authors:
Soraya Lira Alencar a,*, Antonio Osimar Sousa da Silva a, Bruno José Barros da Silva a , Julyane Rocha Santos a, Lenivaldo Valério de Sousa Júnior a, Luciene Santos de Carvalho b, Maritza Montoya Urbina a, Nehemias Rodrigues de Alencar Júnior c
Affiliation: a Laboratório de Síntese de Catalisadores (LSCat)/Centro de Tecnologia (CTEC)/Universidade Federal de Alagoas (UFAL), Maceió, Brazil; b Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal, RN, 59072-970, Brazil; cInstituto Federal de Alagoas (IFAL)/Campus São Miguel dos Campos,São Miguel dos Campos, Brazil
Correspondence: [email protected]
Abstract: Zeolites are aluminosilicates, crystalline, microporous minerals with special properties that allow their application as catalysts, adsorbents and ion exchangers in the chemical and petrochemical industry. Studies are carried out with the aim of finding a economical and viable route for industrial scale production. Parameters influence the crystallization of zeolites, among which: reagent molar fractions (silica, alumina, alkali metal and alkaline earth hydroxides) e temperature. ZSM-12 (MTW) synthesis was studied through conventional (hydrothermal) methodology at different temperatures, and inorganic cations (Li+ and Na+), with the organic structure agent directing MTEACl (methyltriethylammonium chloride). The zeolites synthesized were characterized by X-ray diffraction (XRD), N2 adsorption (BET method), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermal analysis (TG/DTA). The ZSM-12 zeolite was obtained with high purity and crystallinity in 24 h of synthesis at 170 ºC, lower synthesis times than those reported in the literature. By the X-ray diffraction analysis and the Rietveld method, the network parameters of the ZSM-12 zeolite structures confirm their purity and crystallinity.

Title: Oxydation of Cyanide Effluents by Using Active Carbon and Alumina Supports Impregnated with Platinum
Author:
Diana Endara Dranichnikova
Affiliation: Departamento de Metalúrgia Extractiva, Escuela Politécnica Nacional, Quito, Ecuador
Correspondence: [email protected]
Abstract: The extraction of gold has caused significant environmental impacts due to the use of cyanide. Due to the fact that conventional methods do not allow complete degradation of this toxic compound, it has been decided to look for a heterogeneous catalytic oxidation process. For this, alumina-platinum and activated carbon-platinum composites were synthesized by 3 different impregnation processes. The first by continuous agitation of the supports with a solution of 1000 mg/L chloroplatinic acid for 48 h, filtered and dried at 110 °C. The second by complete evaporation of the solution, and the third by direct heating and agitation. The reduction of platinum of all method was carried out in a reducing atmosphere at a temperature of 600 °C for 4 h. Finally, the cyanide ion removal process was carried out using synthetic solutions of sodium cyanide with a concentration of 500 mg/L at a pH of 10.5 and air flow of 180 NL/h. After 8 h, 90% and 95% removal of cyanide was obtained with the alumina and activated carbon composites respectively with a maximum dissolution of platinum of 0.15%, demonstrating that the catalyst can be recovered and reusable without diminishing its catalytic activity.

Title: Photocatalytic Degradation of 2,4,6-Trichlorophenol by MgO-MgFe2O4 Derived from Layered Doble Hydroxides Structure
Authors: Esthela Ramos-Ramírez 1,*, Francisco Tzompantzi-Morales 2, Héctor G. Mojica-Calvillo 1, Norma Gutiérrez-Ortega 3,*, Julio Castillo Rodríguez 2 and Rebeca Jazmín Pérez Rodríguez 1
Affiliation: 1 Departamento de Química, División de Ciencias Naturales y Exactas, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Noria Alta s/n, Col. Noria Alta, 36050 Guanajuato, GTO, Mexico; 2 Departamento de Ingeniería Civil, División de Ingenierías, Universidad de Guanajuato, Juárez No. 77, Col. Centro, 36000 Guanajuato, GTO, México; 3 Universidad Autónoma Metropolitana - Iztapalapa, Depto. Química, División de Ciencias Básicas e Ingeniería, Av. San  Rafael Atlixco No. 186, 09340 Ciudad de México, México
Correspondence: [email protected] and [email protected]
Abstract: In this work, laminar double hydroxides with different Mg / Fe ratio were prepared as precursors of activated photocatalysts presenting band gap energies between 2.28 and 2.47 eV, being values lower than those reported for TiO2-P25. The layered double hydroxides activated at 400 ° C used in the degradation of 2,4,6-trichlorophenol in aqueous solution, showed a high degradation capacity of 92.7% compared to 27.3% of TiO2-P25, which shows a great potential of double layered hydroxides to be used in the photodegradation of chlorophenols that are extremely toxic, especially 2,4,6-trichlorophenol which is potentially carcinogenic and which is found in contaminated effluents.

Title: Use of Mixed Oxides Co/Fe as Heterogeneous Catalysts in Obtaining Biodiesel
Authors: Norma Gutiérrez Ortega a, *, Esthela Ramos Ramírez b, *, Alma Hortensia Serafín-Muñoz a, Adrian Zamorategui-Molina a and José de Jesús Monjaraz-Vallejo b
Affiliation: a Laboratorio de Ingeniería Ambiental/Dpto. de Ingeniería Civil/División de Ingenierías/Universidad de, Guanajuato, Guanajuato, Gto., México; b Laboratorio de Materiales y procesos Avanzados/Dpto. de Química/División de Ciencias Naturales y Exactas/Universidad de Guanajuato, Guanajuato, Gto., México; c Área de Química Aplicada/Departamento de Ciencias Básicas/Unidad Azcapotzalco/Universidad Autónoma Metropolitana, Ciudad de México, México
Correspondence: [email protected] and [email protected]
Abstract: Catalysts of the type of mixed metal oxides with a different Co/Fe ratio were synthesized to be used as heterogeneous catalysts in the production of biodiesel. The effect of the C/Fe ratio on the catalytic capacity in the esterification and transesterification reactions of the fatty acids was analyzed. The physicochemical properties of the catalysts were determined by DRX, TGA and DTA, FTIR, SEM, textural analysis by N2 physisorption and X-ray dispersive energy microanalysis. The quality of biodiesel obtained was determined in accordance with International Standards. Conversion yields of triglycerides to biodiesel of 96% were obtained in 20 minutes of reaction.

Title: Zirconia-supported Silver Nanoparticles for the Catalytic Combustion of Pollutants Originated in Mobile Sources
Authors: Mónica Casella and Ileana D. Lick*
Affiliation: CINDECA (CCT La Plata-CONICET, UNLP), Universidad Nacional de La Plata, Facultad de Ciencias Exactas, 47 N°257, 1900 La Plata, Argentina
Correspondence: [email protected]

Title: Enzymatic Complexes Mixtures Used in the Hydrolysis of Cellulose Obtained from Pre-treated Sugarcane Bagasse with H2SO4/H2O2 in Alkaline Medium
Author: Leila M. A. Campos
Affiliation:
Núcleo de Química Verde, Mestrado em Energia, Universidade Salvador/Laureate Internacional Universities, Bahia – Brasil
Correspondence: [email protected]
Abstract:
Cellulose, a linear polymer of d-glucose, appears as the most widely distributed polysaccharide in nature. There is great interest in the hydrolysis of cellulose for the production of glucose, whose field of activity involves food, fuel and chemical sectors using the concept of biorefinery. Model cellulose substrates have been used for the purpose of studying the mechanisms of enzymatic saccharification. However, the results show that both model cellulose substrates and those obtained from biomass are critical for evaluating the performance of enzymes during the hydrolysis process. Several microorganisms are capable of promoting the biodegradation of cellulose, such as the genera Trichoderma, Aspergillus and Penicillium. In this work, two commercial cocktails of fungal enzymes and combinations of these two systems were used in loads of 10, 20 and 30 FPU/g substrate, in order to investigate the hydrolytic mechanism of cellulose extracted from sugarcane bagasse (BCA) pre-treated with sulfuric acid and hydrogen peroxide, in alkaline medium. This pretreatment method uses sulfuric acid, which favors the solubilization of the hemicellulosic fraction. In addition, the following step with a mixture of hydrogen peroxide and sodium hydroxide provides lignin and hemicellulose solubilization with lower degradation of the cellulosic chain, low production of inhibitors and low precipitation of solid residues, leaving the insoluble fraction enriched in cellulose with small amounts of residual hemicellulose and lignin. The combinations of the two enzymatic complexes used with higher loads (30 FPU/g substrate) showed greater effectiveness in the hydrolysis of cellulose, compared to their individual uses. Scanning electron microscopy (SEM) of the pretreated BCA provided evidence for the significant removal of hemicellulose and lignin, as well as reduction of cellulose crystallinity and consequent increase in the accessibility of enzymes to the cellulosic substrate. The high cost of the enzymes is still a factor that limits their use in the hydrolysis processes; therefore, the use of low enzymatic charges is a key factor for continuing the processes of cellulose conversion into glucose, since the optimization of enzymatic cocktails is related to the choices of enzymes, biomass, and pretreatment applied for improving the synthesis.

Title: Effect of V2O5 during the Reverse Water-gas Shift Reaction (RWGS) over Fe2O3/Cu Catalyst
Authors: Nancy Navarro Ordoñez 1,*, José Luis Benítez Aguilar 2, Patricia Rayo Mayoral 2 and Gloria Alicia del Ángel Montes 1
Affiliation: 1   Departamento de Química, Área de Catálisis, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 189, Cd. México C.P. 09340; [email protected] 2     Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152 San Bartolo Atepehuacan, Gustavo A. Madero, Cd. México C.P. 07730; [email protected]
Correspondence: [email protected]; Tel.: 5560750057
Abstract: The catalytic conversion of CO2 with H2, via the reverse water-gas shift (RWGS) reaction, has been recognized as one of the most promising processes for CO2 utilization. The reverse water-gas shift (RWGS) reaction is a key step in the catalytic hydrogenation of CO2 to CO and the chemical utilization of CO2, especially the generated CO can be used in industry to produce valuable hydrocarbons via Fischer-Tropsch synthesis, and also for the synthesis of methanol, a basic chemical for the production of synthetic fuels and polymers [1-2]. This work includes the development of a new catalyst that is not have been reported in the literature and that has high potential for be scaling to industrial level, it is composed by low cost raw materials and prepared easily, does not requires sophisticated equipment and it could solve the CO2 problem. On this iron-based catalyst the effect of the V2O5 content is studied on the RWGS under moderate conditions of temperature and pressure. The low temperature is one of the most important parameters for the catalyst development, obtained with 1 g of catalysts at atmospheric pressure, GHSV=1800 h-1 and temperature range from 50-150°C, it obtains conversions higher than 72%, this extraordinary result is substantially better than those obtained using the conventional copper-based catalyst, which works at higher temperatures [3].

Catalysts EISSN 2073-4344 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
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