Persona: Guerrero Ruiz, Antonio R
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Guerrero Ruiz
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Antonio R
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Publicación Critical Factors Affecting the Selective Transformation of 5-Hydroxymethylfurfural to 3-Hydroxymethylcyclopentanone Over Ni Catalysts(Chemistry Europe, 2024-06-11) Conesa, José M.; Campos Castellanos, Eduardo; Guerrero Ruiz, Antonio R; Rodríguez Ramos, Inmaculada; Morales Vargas, Mª Virtudes; 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 Selective hydrogenation reactions of 5-hydroxymethylfurfural over Cu and Ni catalysts in water: Effect of Cu and Ni combination and the reagent purity(ELSEVIER, 2023) Morales, María V.; Conesa, José M.; Galvin, Antonio J.; Rodríguez Ramos, Inmaculada; Guerrero Ruiz, Antonio R; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-1848-5985; https://orcid.org/0000-0003-4622-6008This work studies the catalytic properties of Cu and Ni catalysts, as well as the effect of Cu and Ni combination on the activity and selectivity during the aqueous phase hydrogenation of 5-hydroxymethylfurfural (HMF) in a batch reactor, at 60 °C under 30 bar H2. Catalysts with different Ni/Cu ratios (10 wt%) were synthesized over a high surface area graphite (HSAG). While Ni provides the bimetallic catalyst the capacity for hydrogenation of Cdouble bondO and Cdouble bondC groups, Cu contributes to suppress the hydrogenation of the furan ring, reaching a 99% of selectivity to the partial hydrogenated product, 2,5-di-hydroxymethylfuran (DHMF), over 5Cu5Ni/HSAG. The increase of reaction temperature (180 °C) conduced to the hydrolytic ring-opening and rearrangement of HMF. Under such reaction conditions, monometallic Ni afforded the highest yield towards the hydrogenative rearrangement product, 3-hydroxymethylcyclopentanone (81%). However, Cu and CuNi bimetallic catalysts were less reactive to the ring-rearrangement reaction and showed higher tendency to deactivation, especially when the HMF supplier contain sulfur impurities.Publicación Graphite supported heteropolyacid as a regenerable catalyst in the dehydration of 1-butanol to butenes(ELSEVIER, 2023) Conesa, José M.; Morales, María V.; García-Bosch, N.; Rodríguez Ramos, Inmaculada; Guerrero Ruiz, Antonio R; 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 Tunable selectivity of Ni catalysts in the hydrogenation reaction of 5-hydroxymethylfurfural in aqueous media: Role of the carbon supports(ELSEVIER, 2021) Morales, María V.; Conesa, José M.; Rodríguez Ramos, Inmaculada; Guerrero Ruiz, Antonio R; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0001-5470-7958; https://orcid.org/0000-0003-1848-5985; https://orcid.org/0000-0003-4622-6008In addition to the nature of the solvent, the intrinsic metal properties and degree of dispersion, the selective hydrogenation of 5-hydroxymethylfurfural (HMF) has been reported to be greatly affected by the nature of the support. In this work, four Ni catalysts were prepared starting from different carbonaceous supports ─with diverse graphitic and porous structure─ and comparatively evaluated in the hydrogenation reaction of HMF. The reaction was conducted in a batch stirred reactor under 30 bar H2 pressure at 60 °C in aqueous media. Ni supported on a commercial silica and Raney Ni were also tested for reference purposes. We found that carbon supports limit in some extent the reactivity of Ni towards Cdouble bondC hydrogenation, offering higher selectivity to the carbonyl hydrogenated compound, 2,5-di-hydroxymethylfuran (DHMF), in detrimental to the total hydrogenated derivative, 2,5-di-hydroxymethyl-tetrahydrofuran (DHMTHF). However, the latter was the major product over Raney Ni and Ni/SiO2. The unusual catalytic performance of our Ni/carbon catalysts was related to the composition, structural and surface properties. Among all tested Ni/carbon catalysts, Ni over the commercial high surface area graphite (HSAG) exhibited the best catalytic behaviour in terms of DHMF selectivity (90%) and intrinsic catalytic activity. Furthermore, Ni/HSAG displayed satisfactory stability after three consecutive runs.