Palomino Roca, Miguel
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- PublicationCritical Role of Dynamic Flexibility in Ge-Containing Zeolites: Impact on Diffusion(Wiley, 2016-06-11) Gutierrez-Sevillano, Juan José; Calero, Sofia; Hamad, Said; Grau-Crespo, Ricardo; Rey Garcia, Fernando; Valencia Valencia, Susana; Palomino Roca, Miguel; Balestra, Salvador R. G.; Ruiz-Salvador, A. Rabdel; Instituto Universitario Mixto de Tecnología Química; Junta de Andalucía; Ministerio de Ciencia e Innovación; Ministerio de Economía y Competitividad; Royal Society, Reino Unido; European CommissionIncorporation of germanium in zeolites is well known to confer static flexibility to their framework, by stabilizing the formation of small rings. In this work, we show that the flexibility associated to Ge atoms in zeolites goes beyond this static effect, manifesting also a clear dynamic nature, in the sense that it leads to enhanced molecular diffusion. Our study combines experimental and theoretical methods providing evidence for this effect, which has not been described previously, as well as a rationalization for it, based on atomistic grounds. We have used both pure-silica and silico-germanate ITQ-29 (LTA topology) zeolites as a case study. Based on our simulations, we identify the flexibility associated to the pore breathing-like behavior induced by the Ge atoms, as the key factor leading to the enhanced diffusion observed experimentally in Ge-containing zeolites.
- PublicationSintesis y caracterización de membranas de zeolita para separación de gases(Universitat Politècnica de València, 2014-05-12) Palomino Roca, Miguel; Soriano Costa, Enrique; Instituto Universitario Mixto de Tecnología QuímicaProyecto Confidencial
- PublicationCobalt(II) Bipyrazolate Metal-Organic Frameworks as Heterogeneous Catalysts in Cumene Aerobic Oxidation: A Tag-Dependent Selectivity(American Chemical Society, 2020-06-15) Nowacka, Anna Elzbieta; Vismara, R.; Mercuri, G.; Moroni, M.; Palomino Roca, Miguel; Domasevitch, K.; di Nicola, C.; Pettinari, C.; Giambastiani, G.; Llabrés I Xamena, Francesc Xavier; Galli, S.; Rossin, A.; Instituto Universitario Mixto de Tecnología Química; European Commission; Università degli Studi di Camerino; Università degli Studi dell'Insubria; Ministerio de Economía y Competitividad; Agence Nationale de la Recherche, Francia; Ministero dell'Istruzione dell'Università e della Ricerca, Italia; Agencia Estatal de Investigación[EN] Three metal-organic frameworks with the general formula Co(BPZX) (BPZX(2-) = 3-X-4,4'-bipyrazolate, X = H, NH2, NO2) constructed with ligands having different functional groups on the same skeleton have been employed as heterogeneous catalysts for aerobic liquid-phase oxidation of cumene with O-2 as oxidant. O-2 adsorption isotherms collected at p(O2) = 1 atm and T = 195 and 273 K have cast light on the relative affinity of these catalysts for dioxygen. The highest gas uptake at 195 K is found for Co(BPZ) (3.2 mmol/g (10.1 wt % O-2)), in line with its highest BET specific surface area (926 m(2)/g) in comparison with those of Co(BPZNH(2)) (317 m(2)/g) and Co(BPZNO(2)) (645 m(2)/g). The O-2 isosteric heat of adsorption (Q(2)) trend follows the order Co(BPZ) > Co(BPZNH(2)) > Co(BPZNO(2)). Interestingly, the selectivity in the cumene oxidation products was found to be dependent on the tag present in the catalyst linker: while cumene hydroperoxide (CHP) is the main product obtained with Co(BPZ) (84% selectivity to CHP after 7 h, p(O2) = 4 bar, and T = 363 K), further oxidation to 2-phenyl-2-propanol (PP) is observed in the presence of Co(BPZNH(2)) as the catalyst (69% selectivity to PP under the same experimental conditions).
- PublicationLTA/Poly(1-trimethylsilyl-1-propyne) Mixed-Matrix Membranes for High-Temperature CO2/N2 Separation(Wiley-VCH Verlag, 2015) Fernández-Barquín, Ana; Casado-Coterillo, Clara; Palomino Roca, Miguel; Valencia Valencia, Susana; Irabien, Ángel; Instituto Universitario Mixto de Tecnología Química; Ministerio de Economía y Competitividad; Universidad de CantabriaMixed-matrix membranes (MMM) consisting of poly(1-trimethylsilyl-1-propyne) (PTMSP) as continuous matrix and small-pore LTA-framework zeolites with Si/Al ratios from 1 (commercial zeolite A) to ¥ (ITQ-29) as dispersed phase were prepared by solution casting. The thermal stability of the MMM is as high as that of glassy PTMSP polymer, whose high permeability is maintained even at increasing temperature. The effect of the Si/Al ratio in the zeolite fillers on the membrane performance is observed by the increasing CO2/N2 permselectivity of low-Si/Al ratio zeolite A-based membranes, in comparison with pure silica ITQ-29. The performance of the LTA-type zeolite-PTMSP MMM was adjusted to the modified Maxwell model by estimating the chain immobilization factor and the interphase thickness as a function of temperature, Si/Al ratio, and zeolite loading
- PublicationHigh Proton Conductivity in a Flexible, Cross-Linked, Ultramicroporous Magnesium Tetraphosphonate Hybrid Framework(American Chemical Society, 2012) Colodrero, Rosario M. P.; Olivera-Pastor, Pascual; Losilla, Enrique R.; Hernández-Alonso, Daniel; Aranda, Miguel A. G.; León-Reina, Laura; Rius, Jordi; Demadis, Konstantinos D.; Moreau, Bernard; Villemin, Didier; Palomino Roca, Miguel; Rey Garcia, Fernando; Cabeza, Aurelio; Instituto Universitario Mixto de Tecnología QuímicaMultifunctional materials, especially those combining two or more properties of interest, are attracting immense attention due to their potential applications. MOFs, metal organic frameworks, can be regarded as multifunctional materials if they show another useful property in addition to the adsorption behavior. Here, we report a new multifunctional light hybrid, MgH6ODTMP·2H2O(DMF)0.5 (1), which has been synthesized using the tetraphosphonic acid H8ODTMP, octamethylenediamine-N,N,N'N'-tetrakis(methylenephosphonic acid), by highthroughput methodology. Its crystal structure, solved by Patterson-function direct methods from synchrotron powder Xray diffraction, was characterized by a 3D pillared open framework containing cross-linked 1D channels filled with water and DMF. Upon H2O and DMF removal and subsequent rehydration, MgH6ODTMP·2H2O (2) and MgH6ODTMP·6H2O (3) can be formed. These processes take place through crystalline-quasi-amorphous-crystalline transformations, during which the integrity of the framework is maintained. A water adsorption study, at constant temperature, showed that this magnesium tetraphosphonate hybrid reversibly equilibrates its lattice water content as a function of the water partial pressure. Combination of the structural study and gas adsorption characterization (N2, CO2, and CH4) indicates an ultramicroporous framework. High-pressure CO2 adsorption data are also reported. Finally, impedance data indicates that 3 has high proton conductivity at T = 292 K at aprox. 100% relative humidity with an activation energy of 0.31 eV.
- PublicationA highly stable and hierarchical tetrathiafulvalene-based metal organic framework with improved performance as a solid catalyst(The Royal Society of Chemistry, 2018-03) Souto, Manuel; Santiago-Portillo, Andrea; Palomino Roca, Miguel; Vitorica-Yrezabal, Iñigo J.; Vieira, Bruno J. C.; Waerenborgh, João C.; Valencia Valencia, Susana; Navalón Oltra, Sergio; Rey Garcia, Fernando; García Gómez, Hermenegildo; Minguez Espallargas, Guillermo; Instituto Universitario Mixto de Tecnología Química; Departamento de Química; Escuela Técnica Superior de Ingeniería Industrial; Grupo de Fotoquímica Heterogénea y Medioambiental; European Regional Development Fund; Ministerio de Economía y Competitividad; Fundação para a Ciência e a Tecnologia, Portugal; Agencia Estatal de Investigación[EN] Herein we report the synthesis of a tetrathiafulvalene (TTF)-based MOF, namely MUV-2, which shows a non-interpenetrated hierarchical crystal structure with mesoporous one-dimensional channels of ca. 3 nm and orthogonal microporous channels of ca. 1 nm. This highly stable MOF (aqueous solution with pH values ranging from 2 to 11 and different organic solvents), which possesses the well-known [Fe3(¿3-O)(COO)6] secondary building unit, has proven to be an efficient catalyst for the aerobic oxidation of dibenzothiophenes.
- PublicationOriented CoSAPO-5 Membranes by Microwave-Enhanced Growth on TiO2-Coated Porous Alumina(Wiley-VCH Verlag, 2012-01-27) Stoeger, Jared A.; Palomino Roca, Miguel; Agrawal, Kumar Varoon; Zhang, Xueyi; Karanikolos, Georgios N.; Valencia Valencia, Susana; Corma Canós, Avelino; Tsapatsis, Michael; Instituto Universitario Mixto de Tecnología Química; European Commission; Petroleum Institute of Abu Dhabi; National Science Foundation, EEUU[EN] Microwaving plates: A facile method was developed for the fabrication of preferentially c-oriented cobalt-substituted silicoaluminophosphate-5 (CoSAPO-5) membranes on porous alumina supports. In situ microwave growth using a slip-coated TiO2 layer on the support surface resulted in an oriented CoSAPO-5 crystal layer, which was evolved into a defect-free membrane by improving crystalline intergrowth through secondary hydrothermal microwave growth.
- PublicationCobalt Metal Organic Framework Based on Two Dinuclear Secondary Building Units for Electrocatalytic Oxygen Evolution(American Chemical Society, 2019-12-18) Gutiérrez Tarriño, Silvia; Olloqui Sariego, José Luis; Calvente, Juan José; Palomino Roca, Miguel; Mínguez Espallargas, Guillermo; Jorda Moret, Jose Luis; Rey Garcia, Fernando; Oña Burgos, Pascual; Instituto Universitario Mixto de Tecnología Química; Departamento de Química; Escuela Técnica Superior de Ingeniería Industrial; Ministerio de Ciencia e Innovación; Universitat Politècnica de València; Ministerio de Economía y Competitividad[EN] The synthesis of a new microporous metal-organic framework (MOF) based on two secondary building units, with dinuclear cobalt centers, has been developed. The employment of a well-defined cobalt cluster results in an unusual topology of the Co-2-MOF, where one of the cobalt centers has three open coordination positions, which has no precedent in MOF materials based on cobalt. Adsorption isotherms have revealed that Co-2-MOF is in the range of best CO2 adsorbents among the carbon materials, with very high CO2/CH4 selectivity. On the other hand, dispersion of Co-2-MOF in an alcoholic solution of Nafion gives rise to a composite (Co-2-MOF@Nafion) with great resistance to hydrolysis in aqueous media and good adherence to graphite electrodes. In fact, it exhibits high electrocatalytic activity and robustness for the oxygen evolution reaction (OER), with a turnover frequency number value superior to those reported for similar electrocatalysts. Overall, this work has provided the basis for the rational design of new cobalt OER catalysts and related materials employing well-defined metal clusters as directing agents of the MOF structure.
- PublicationTuning the Adsorption Properties of Zeolites as Adsorbents for CO2 Separation: Best Compromise between the Working Capacity and Selectivity(American Chemical Society, 2014-06-11) García, Edder J.; Pérez-Pellitero, Javier; Pirngruber, Gerhard D.; Jallut, Christian; Palomino Roca, Miguel; Rey Garcia, Fernando; Valencia Valencia, Susana; Instituto Universitario Mixto de Tecnología QuímicaThe choice of an appropriate adsorbent for CO2 separation by pressure-swing adsorption remains a field of intense research. In this work, several FAU and LTA zeolites with different Na contents (Si/Al ratios) are studied for the separation of CO2 from mixtures of CO2, CO, and CH4 by means of breakthrough experiments. The breakthrough experiments were carried out between 1 and 5 bar at 303 K using two feed mixtures: 50/50 (v/v) CO2/CH4 and 75/15/15 (v/v/v) CO2/CH4/CO. The most polar zeolites, i.e., those with high Na content, exhibit the highest adsorption capacity and selectivity for CO2, but their regeneration is difficult; hence, their working capacity is low. The opposite is true for the least polar zeolites, i.e., those with low Na content. In order to quantify the trade-off between the selectivity and working capacity, the Ruthven statistical model (RSM) was used. It satisfactorily reproduced the experimental trends. We, therefore, used the RSM to identify the properties of the adsorbent that lead to an optimal compromise between the working capacity and separation factor. The critical parameter is the concentration of extraframework cations, which, in turn, depends on the framework charge of the zeolites FAU and LTA. The optimal trade-off zone is defined in terms of the Henry constant of CO2 (KCO2). It is found that this zone is placed between KCO2 = 5 × 10 3 and 50 × 10 3 molecules·bar 1·Å 3. This interval corresponds to a heat of adsorption of CO2 at zero coverage between 27 and 32 kJ·mol 1. In our study, this optimal range of Henry constants was achieved for the zeolites Na-USY, SAPO-37, LTA (Si/Al = 5), and EMC-1.
- PublicationZeolite Rho: a highly selective adsorbent for CO2/CH4 separation induced by a structural phase modification(Royal Society of Chemistry, 2012) Palomino Roca, Miguel; Corma Canós, Avelino; Jorda Moret, Jose Luis; Rey Garcia, Fernando; Valencia Valencia, Susana; Instituto Universitario Mixto de Tecnología Química; European Commission; Ministerio de Ciencia e Innovación[EN] Zeolite Rho is able to successfully separate CO2 from CH4 with the highest selectivity ever observed on the basis of pore diameter and surface polarity. The adsorption of CO2 provokes structural changes in the zeolite Rho.