Persona: Guerrero Ruiz, Antonio R
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aguerrero@ccia.uned.es
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0000-0003-1848-5985
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Guerrero Ruiz
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Antonio R
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Publicación Effect of surface, structural and textural properties of graphenic materials over cooperative and synergetic adsorptions of two chloroaromatic compounds from aqueous solution(ELSEVIER, 2018) Esteban Arranz, Adrián; Tordesillas, Compte; Muñoz Andrés, Vicenta; Pérez Cadenas, María; Guerrero Ruiz, Antonio R; https://orcid.org/0000-0003-4953-8066; https://orcid.org/0000-0003-1848-5985Graphenic materials have been recently applied for adsorption processes due to their high efficiency and their easy capability of surface modification. In the present study two different graphene oxides, two reduced graphene oxides under inert atmosphere and one reduced graphene oxide under ammonia atmosphere were used as adsorbents for removing two chloroaromatic compounds from water: 2,4-dichlorophenol and 2,4-dichlorophenoxyacetic acid. Hydrogen bonds and πsingle bondπ interactions have been detected by Attenuated Total Reflectance infrared spectroscopy in the solids with adsorbed species. Besides, two direct relationships between their adsorption capacities and graphenic surface, textural and structural properties were found. In order to obtain real adsorption information, some experiments with the presence of both pollutants at the same time were performed. From these mixture experiments, when graphene oxide was used as adsorbent some cooperative effects between pollutants were detected. Based on XRD results and an innovative comparison between different infrared techniques, the importance of interlayer spaces during adsorption was demonstrated. Otherwise, synergetic interactions between pollutants were revealed as the main adsorption forces when reduced graphene oxides were used, being their aromatic structures a decisive factor in their final adsorption capacity.Publicación Formic Acid Dehydration Using Mechanochemically Prepared TiO2-Graphite Composites(Wiley, 2024-07-27) Yruela Garrido, Marta; Martín Rodríguez, Nuria; Castillejos López, Eva; Campos Castellanos, Eduardo; Rodríguez Ramos, Inmaculada; Guerrero Ruiz, Antonio R; Conesa Alonso, José MaríaCommercial high surface area graphite (HSAG300) and commercial TiO2 were used to produce composite materials through a simple mechanochemical method involving milling and ultrasonic treatments. The acid and basic sites exposed on the surfaces of these materials were characterized by temperature-programmed desorption (TPD) of ammonia and carbon dioxide. The catalytic materials were tested in the dehydration reaction of formic acid to produce hydrogen-free CO. While HSAG300 is practically inactive under reaction conditions (continuous gas flow at temperatures in the range of 100–250 °C), all samples containing TiO2 are active, exhibiting high selectivity to CO without significant deactivation at moderate reaction temperatures. It is demonstrated that the presence of graphite in the catalysts enhances the specific catalytic activity of TiO2. Assuming that the dehydration reaction is catalyzed by acid sites on the TiO2 surfaces, a comparative evaluation of the surface sites reveals that the graphite-TiO2 interactions not only change the density of surface sites but also modify the strength of the acid centers of TiO2. In summary, the interaction of HSAG300 with TiO2 modulates the surface properties of the prepared composite catalysts, decreasing the total number of basic surface sites and increasing the strength of acidic sites compared to bare TiO2.Publicación Graphite supported heteropolyacid as a regenerable catalyst in the dehydration of 1-butanol to butenes(ELSEVIER, 2023) Morales, María V.; García-Bosch, N.; Rodríguez Ramos, Inmaculada; Guerrero Ruiz, Antonio R; Conesa Alonso, José María; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-1848-59851-butanol dehydration reaction has recently emerged as a sustainable route to produce butenes which can be further oligomerized to be applied as jet fuel. However, the high catalyst deactivation rates observed during this reaction due to coke deposition is still a pending matter. As promising catalysts for this reaction, we have supported two heteropolyacids (HPA), i.e. H4SiW12O40 (STA) and H3PW12O40 (TPA), on two commercial carbon materials: an activated carbon (AC) and a high surface area graphite (HSAG). Aiming to evaluate the role of HPA-support interactions, the STA was also dispersed over metallic oxides of different acidic nature, namely SiO2, Al2O3 and ZrO2. An exhaustive physicochemical characterization revealed that after the HPA dispersion thorough the support, the Keggin structure was maintained and an increase in the amount and strength of acid sites was provoked, but in different degree according to the HPA type and support’s nature. While the TPA-based catalysts developed less quantity of total acid sites, but higher strength than their STA-carbon counterparts, the STA/AC and TPA/AC samples exhibited a slight major amount of acid sites than STA/HSAG and TPA/HSAG. The HPA-support interactions have ultimately modulated to some extent the activity, selectivity, stability and regeneration ability of the synthesized catalysts, when applied in the gas phase butanol dehydration reaction at 275 °C. The higher STA decomposition temperature prompted by the graphitic support, among other factors, allowed the total regeneration of the highly active (39 mmolBuOH∙min−1∙ga.p) and n-butenes selective (>98 %) STA/HSAG catalyst by means of combustion of carbon deposits at 400 °C.Publicación Premio Nobel de Química(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2008-01-01) Guerrero Ruiz, Antonio RPublicación Novedades científicas en Química en el año 2003(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2004-01-01) Criado Sancho, Manuel; Guerrero Ruiz, Antonio RPublicación Critical Factors Affecting the Selective Transformation of 5-Hydroxymethylfurfural to 3-Hydroxymethylcyclopentanone Over Ni Catalysts(Chemistry Europe, 2024-06-11) Campos Castellanos, Eduardo; Guerrero Ruiz, Antonio R; Rodríguez Ramos, Inmaculada; Morales Vargas, Mª Virtudes; Conesa Alonso, José María; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0001-5470-7958; https://orcid.org/0000-0003-4622-6008The ring-rearrangement of 5-hydroxymethylfurfural (HMF) to 3-hydroxymethylcyclopentanone (HCPN) was investigated over Ni catalysts supported on different carbon supports and metallic oxides with different structure and acid-base properties. Their catalytic performance was tested in a batch stirred reactor in aqueous solution at 180 °C and 30 bar of H2. Under these conditions, the HMF hydrogenation proceeds through three possible competitive routes: (i) a non-water path leading to the total hydrogenation product, 2,5-di-hydroxymethyl-tetrahydrofuran (DHMTHF), and two parallel acid-catalyzed water-mediated routes responsible for (ii) ring-opening and (iii) ring-rearrangement reaction products. All catalyst systems primarily produced HCPN, but reaction rates and product distribution were influenced by several variables, some of them intensely analyzed in this work. The most proper conditions resulted to be the presence of the medium/strong Lewis's acidity of a Ni/ZrO2 catalyst (initial TOF=5.99 min−1 and 73 % HCPN selectivity) or the Brønsted acidity originated by an oxidized high surface area graphite, Ni/HSAG-ox (initial TOF=5.92 min−1 and 87 % HCPN selectivity). However, too high density of acidic sites on the catalyst support (Ni/Al2O3) and sulfur impurities from the HMF feedstock led to catalyst deactivation by coke deposition and Ni poisoning, respectively.Publicación Cu and Pd nanoparticles supported on a graphitic carbon material as bifunctional HER/ORR electrocatalysts(ELSEVIER, 2020-11-01) Nunes, Marta S.; Fernandes, Diana M.; Morales, M. V.; Rodríguez Ramos, Inmaculada; Freire, Cristina; Guerrero Ruiz, Antonio R; https://orcid.org/0000-0002-0460-451X; https://orcid.org/0000-0001-5263-2737; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-4622-6008; https://orcid.org/0000-0003-1848-5985The development of efficient, available and robust substitutes for the Pt-based electrocatalysts is very important for a sustainable energetic future. Herein, we report a series of composites based on Cu, Pd and Cu-Pd nanoparticles (NPs) supported on high surface area graphite (HSAG), as electrocatalysts for the energy-related reduction reactions – oxygen reduction (ORR) and hydrogen evolution (HER) reactions. All the composites showed interesting ORR electrocatalytic activities in alkaline medium. The Pd/HSAG and Cu-Pd/HSAG composites exhibited the most promising performances, with onset potentials of 0.84 and 0.91 V and current densities of jL, 0.3 V, 1600 rpm=−3.5 and −4.2 mA cm−2, respectively. All the composites showed selectivity for the 4-electron process and Tafel slopes in the range 48–77 mV dec−1. The metal/HSAG composites revealed a great tolerance to methanol and moderate electrochemical stability. In highly acidic medium (0.5 mol dm−3 H2SO4, pH=0.3) only the Cu-Pd/HSAG and Pd/HSAG electrocatalysts presented electrocatalytic activity toward HER, with relative low overpotentials (η10=0.145 and 0.063 V, respectively), small Tafel slopes (75 and 42 mV dec−1) and similar exchange current densities (0.43 and 0.57 mA cm−2). These electrocatalysts also showed moderate electrochemical stability, in particular Cu-Pd/ HSAG for which overpotential only changed between 0.033 and 0.038 V for j=40mAcm−2. The results showed that only small loading of Pd NPs (1 wt.% Pd) was able to improve significantly the ORR/ HER electrocatalytic activity, which is a very important outcome to rationalize the design of efficient and costeffective electrocatalysts in future.Publicación Continuous Catalytic Condensation of Ethanol into 1‑Butanol: The Role of Metallic Oxides (M = MgO, BaO, ZnO, and MnO) in Cu-M/ Graphite Catalysts(ACS Publications, 2020) López Olmos, Cristina; Morales, María V.; Rodríguez Ramos, Inmaculada; Guerrero Ruiz, Antonio R; Guerrero-Ruiz, Antonio; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-1848-5985; https://orcid.org/0000-0003-4622-6008Bifunctional catalysts supported over high-surface-area graphite comprising copper and a series of metallic oxides (MgO, BaO, ZnO, or MnO) that exhibit different acid/base properties were studied in the ethanol condensation reaction to 1- butanol in a continuous flow reactor. This condensation reaction goes through the Guerbet mechanism, consisting of a multistep process based on hydrogenation/dehydrogenation reactions as well as base-catalyzed aldol condensation and acid-catalyzed dehydration reactions. The catalytic tests were performed in a fixed-bed reactor working in the gas phase at 50 bar and 503 K. The catalyst 5Cu-Mn/G exhibited the highest yield toward 1-butanol followed closely by 5Cu-Mg/G, unlike their counterparts with BaO and ZnO as the metal oxide. The cooperative action between the metal function as the hydrogenating/dehydrogenating agent and the suitable quantity of medium-high-strength basic sites and medium-weak-strength acid sites is responsible for the highest 1- butanol yields.Publicación Nuevos materiales: Catalizadores heterogéneos de alta especificidad(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2005-01-01) Rodríguez Ramos, Inmaculada; Bachiller Baeza, Belén; Guerrero Ruiz, Antonio R; Asedegbega Nieto, EstherPublicación Tesis Doctorales: "Nuevos nanomateriales aplicados como catalizadores para algunos procesos de valorización de productos derivados de la biomasa"(Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias, 2018-01-01) Guerrero Ruiz, Antonio R; Castillejos López, Eva