Persona: Martín Aranda, Rosa María
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0000-0001-5628-8144
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Martín Aranda
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Rosa María
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Publicación SiO2 supported niobium oxides with active acid sites for the catalytic acetalization of glycerol(Elsevier, 2020-10-01) Kao, Li Chen; Kan, Wen Chen; Guerrero Pérez, María Olga; Bañares, Miguel Ángel; Ya Hsuan Liou, Sofía; Martín Aranda, Rosa MaríaThe silica supported niobium oxide catalysts with abundant acid active sites were successfully fabricated and demonstrated catalytic activity in the acetalization of glycerol with acetone to produce solketal. Although Niobium pentachloride which was used as the niobium precursor preferred to aggregate on the surface, the chemical vapor deposition method was introduced to remove the surface chloride. The synthesis parameter of the material affects the structure and the type of the supported niobium oxide on the carrier, and directly changes the amounts of catalytic sites. The effect of calcination temperature/time and loading amount of hydrated niobium oxide on the catalytic performance was investigated. The properties of acid sites on catalysts were characterized, and the catalytic process was directly observed by operando Raman. These in-situ experimental trials could provide deep insight to understand the catalytic mechanism.Publicación Developing strategies for the preparation of Co-carbon catalysts involved in the free solvent selective synthesis of aza-heterocycles(Elsevier, 2018-02) Godino Ojer, Marina; Pérez Cadenas, Agustín Francisco; Pérez Mayoral, María Elena; Martín Aranda, Rosa MaríaWe report herein different series of new zero valent Cobalt nanocarbons, as doped and supported aerogels, able to efficiently catalyze the reaction of 2-amino-5-chlorobenzaldehyde and -ketoesters, via Friedländer reaction. The reaction works under solvent-free and mild conditions affording yields over 80% in only 30 min of reaction time. The catalysts could be reused almost during two consecutive cycles without almost any activity loss. A comparative study between supported and doped-carbon aerogels, as catalysts highly efficient in the reaction, has allowed to stablish the relationship between the catalyst structure and the catalytic performance. At this regard, different parameters such as carbonization temperature and surface chemistry on the aerogels under study have been also explored. As a result, although the carbon matrix is involved in the reaction, the Co(0) nanoparticles on the carbon surface are the predominant active catalytic species. Oxygen functionalities on the oxidized samples in the surroundings of Co(0) nanoparticles probably prevent the access of the reagents, notably decreasing their catalytic performance.Publicación Impact of Brønsted acid sites in MWW zeolites modified with cesium and amine species on Knoevenagel condensation(Elsevier, 2019-05-15) Wojtaszek Gurdak, Anna; Grzesinska, Aneta; Ziolek, María; Calvino Casilda, Vanesa; Martín Aranda, Rosa MaríaLayered zeolites of MWW family, MCM-22 and pillared MCM-36, were used as supports for base modifiers: cesium species (introduced via cation exchange or impregnation) and 3-aminopropyl trimethoxysilane (AP). The obtained materials were characterized by different methods (ICP-OES, N2 adsorption, XRD, XPS, TG/DTA, FTIR combined with pyridine adsorption, 2-propanol decomposition) for evaluation of chemical, structural and surface properties. All materials obtained were subjected to the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate and ethyl acetoacetate. The effect of the zeolite structure, the stability of the catalysts as well as acid-base properties of zeolites on the activity in Knoevenagel condensation were considered. Of particular interest was the role of Brønsted acid sites (BAS). The nature of basic sites and BAS played different roles depending on the methylene compound used in the Knoevenagel condensation. AP-modified zeolites were the most active in the condensation between benzaldehyde and ethyl cyanoacetate, in which, in the first step of the reaction AP abstracted hydrogen from methylene carbon in ethyl cyanoacetate. A different reaction pathway was postulated for the condensation with ethyl acetoacetate on the basis of the highest activity of unmodified zeolites and the relationship between benzaldehyde conversion and the number of BAS. For this reaction protonation of benzaldehyde was postulated as the initial step of the reaction.Publicación Catálisis heterogénea y radiación microondas, una tecnología alternativa para un desarrollo sostenible(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2008-01-01) Calvino Casilda, Vanesa; Martín Aranda, Rosa María; López Peinado, Antonio JoséPublicación Enseñanza de las Ciencias: El wolframio: elemento químico español. Juan José y Fausto Elhuyar, sus descubridores(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2007-01-01) Blasco Jiménez, Davínia; Perozo Rondón, Elizabeth; Ferrera Escudero, Santiago; Ávila Rey, María Jesús; Calvino Casilda, Vanesa; López Peinado, Antonio José; Martín Aranda, Rosa MaríaPublicación Ammonium acetate as a novel buffer for highly selective robust urinary HPLC-ICP-MS arsenic speciation methodology(Elsevier, 2021-01-01) Rodríguez, P. F.; López Colón, José Luis; Mendoza, J. L. de; Martín Aranda, Rosa MaríaAmmonium acetate is employed in order to develop a novel HPLC-ICP-MS arsenic speciation methodology applicable to six arsenic species, i.e, AC, AB, AsIII, AsV, DMA and MMA. The most predominant species in the toxicological field are covered in a 30-min chromatogram with reproducible and repeatability peak area ratio. Moreover, typical problems from traditional methods are sorted out by using a robust, high-selective and 75ArCl+ interference-free methodology. Chromatographic and detector optimization ensures low LOQs for each species with acceptable precision and accuracy values obtained using four urinary arsenic speciation PTS enabling to be useful for sub ng mL−1 arsenic exposure assessments.Publicación Semblanzas de científicas y científicos españoles: Avelino Corma Canós(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2016-01-01) Martín Aranda, Rosa MaríaPublicación Colaboraciones en Ciencias de la Naturaleza: Entrevista a José Ignacio Monreal Bueno, fiscal de medio ambiente de Tarragona(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2017-01-01) Martín Aranda, Rosa MaríaPublicación Presentación de los futuros Grados de la Facultad de Ciencias : Grado en Ciencias Ambientales(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2008-01-01) Perea Cobarrubias, Alvaro; Martín Aranda, Rosa MaríaPublicación Enseñanza de las Ciencias: El platino, metal descubierto por el español Antonio de Ulloa(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2006-01-01) Perozo, Elízabeth; Ferrera Escudero, Santiago; Blasco, Davinia; Costarrosa, Laureano; Avila, María Jesús; Calvino Casilda, Vanesa; López Peinado, Antonio José; Martín Aranda, Rosa María