Jorge Gascon

Delft University of Technology, Delft, South Holland, Netherlands

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Publications (111)540 Total impact

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    ABSTRACT: A combined experimental and simulation study for the separation of carbon dioxide and methane mixtures using NH2-MIL-53(Al) as adsorbent is presented. A fixed-bed model has been applied to simulate binary breakthrough experiments obtained in small lab-scale equipment (10 cm column, 1/4″ in diameter, 800 mg sample). A mixed Langmuir/Langmuir-Freundlich isotherm is used to capture the temperature dependence of the two-step isotherm and a linear driving force model to capture diffusion in the MOF crystals. The model is able to describe the experimental breakthrough data at 273 K over a pressure range of 1 to 20 bar. Displacement of methane by carbon dioxide, a large apparent roll-up effect, heats of adsorption and dispersion phenomena have been quantified taking into account post-column volumes often present in lab-scale equipment. The heat effects result in a maximum local temperature rise up to 20 K.
    Chemical Engineering Science 03/2015; 124:96-108. · 2.61 Impact Factor
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    ABSTRACT: A heterogeneous molecular catalyst based on Ir(III) Cp* (Cp*=pentamethylcyclopentadienyl) attached to a covalent triazine framework (CTF) is reported. It catalyses the production of hydrogen from formic acid with initial turnover frequencies (TOFs) up to 27 000 h(-1) and turnover numbers (TONs) of more than one million in continuous operation. The CTF support, with a Brunauer-Emmett-Teller (BET) surface area of 1800 m(2) g(-1) , was constructed from an optimal 2:1 ratio of biphenyl and pyridine carbonitrile building blocks. Biphenyl building blocks induce mesoporosity and, therefore, facilitate diffusion of reactants and products whereas free pyridinic sites activate formic acid towards β-hydride elimination at the metal, rendering unprecedented rates in hydrogen production. The catalyst is air stable, produces CO-free hydrogen, and is fully recyclable. Hydrogen production rates of more than 60 mol L(-1) h(-1) were obtained at high catalyst loadings of 16 wt % Ir, making it attractive towards process intensification. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    ChemSusChem 02/2015; · 7.48 Impact Factor
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    ABSTRACT: The effect of synthesis pH and H2O/EtOH molar ratio on the textural properties of different aluminium trimesate metal organic frameworks (MOFs) prepared in the presence of the well-known cationic surfactant cetyltrimethylammonium bromide (CTAB) at 120 °C was studied with the purpose of obtaining a MOF with hierarchical pore structure. Depending on the pH and the solvent used, different topologies were obtained (namely, MIL-96, MIL-100 and MIL-110). On the one hand, MIL-110 was obtained at lower temperatures than those commonly reported in the literature and without additives to control the pH; on the other hand, MIL-100 with crystallite sizes as small as 30 ± 10 nm could be easily synthesized in a mixture of H2O and EtOH with a H2O/EtOH molar ratio of 3.4 at pH 2.6 in the presence of CTAB. The resulting material displays a hierarchical porosity that combines the microporosity from the MOF and the non-ordered mesopores defined in between the MOF nanoparticles. Interestingly, the maximum of the pore size distribution could be varied between 3 and 33 nm. Finally, at pH 2.5 and using water as a solvent, platelets of MIL-96, a morphology never observed before for this MOF, were synthesized with a (001) preferential crystal orientation, the (001) plane running parallel to the bipyramidal cages of the MIL-96 topology.
    CrystEngComm 01/2015; 17(7):1693-1700. · 3.86 Impact Factor
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    ABSTRACT: Multiphase catalytic processes involve the combination of scale-dependent and scale-independent phenomena, often resulting in a compromised, sub-optimal performance. The classical approach of randomly packed catalyst beds using unstructured catalyst particles may be outperformed by the careful design of the catalyst at the nano-scale and by the judicious choice and design of reactor. Application of structured catalysts and reactor internals and the combination of advanced reactor and catalyst systems with in situ separation allow decoupling the various phenomena involved, opening the way to intensified processes on a large scale. The integral approach of Catalysis and Reaction Engineering discussed here will play a pivotal role in the development of novel, future-proof processes.
    Catal. Sci. Technol. 12/2014;
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    ABSTRACT: We report a series of powder X-ray diffraction experiments performed on the soft porous crystals MIL-53(Al) and NH2-MIL-53(Al) in a diamond anvil cell under different pressurization media. Systematic refinements of the obtained powder patterns demonstrate that these materials expand along a specific direction while undergoing total volume reduction under an increasing hydrostatic pressure. The results confirm for the first time the negative linear compressibility behaviour of this family of materials, recently predicted from quantum chemical calculations.
    CrystEngComm 12/2014; 17(2). · 3.86 Impact Factor
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    ABSTRACT: Abstracts: * Porous aromatic polymers as heterogeneous catalysts.pdf (182.8KB) - Uploading Abstracts
    14 AIChE Annual Meeting; 11/2014
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    ABSTRACT: Adsorptive characterization using nitrogen at 77 K is one of the most widely used techniques to assess textural properties of porous adsorbents. Especially the pore volume, specific surface area and pore size distribution are frequently reported. Despite the fact that most popular methods to deduce these quantities, the method posed by Brunauer, Emmet and Teller (BET) [1] for the specific surface area and the method developed by Barrett, Joyner and Halenda (BJH) for pore the pore size distribution, [2] have been used for many decades, there are still inconsistencies in the exact calculation procedure of these methods and still wrong and/or statistically insignificant conclusions therefrom, as will be elucidated in detail in this contribution. Based on a thorough error analysis on the accuracy of volumetric nitrogen adsorption measurements, the influence of experimental uncertainties is analysed. This yields not only insights in the uncertainty in derived properties (pore volume, BET surface area and BJH pore size-distribution) but also generates practical recommendations to optimize accuracy of N2 adsorption measurements. Consequently, guidelines are developed to obtain representable accurate textural properties. Especially the derivation of specific surface areas requires attention, as erroneous results are easily obtained. A variety of sorbents (MOFs, zeolite, activated carbon and alumina) has been used in this work to ensure that obtained conclusions and posed guidelines hold for a wide range of commonly used porous materials. For (BJH) pore size distributions, statistically irrelevant or highly inaccurate results are frequently obtained. MIL-101, arguably the metal-organic framework (MOF) most reported on, has been characterized by a multitude of researchers and serves thus well to exemplify the current state of characterization using N2 sorption in literature. In many cases the determination of pore volume and specific surface areas has been executed wrongly and underlines a clear potential for standardized determination conditions for textural properties. In summary, to improve the meaningfulness of derived properties and to minimize statistical uncertainties, practical recommendations and guidelines are proposed for experimental operation variables and data analysis. Some of these are: * The relative uncertainty in pore volume is lowest when the Vmanifold/Vcell ratio is between 2 and 3. * A simple two-point BET method is proposed to determine a priori the upper relative pressure boundary of the BET window (close to saturation), as alternative to the method reported by Rouquerol et al. * For the lower relative pressure limit determination it is suggested to analyse Studentized residuals. Provided the model isotherm is correct, data points become eligible for possible exclusion when | resis| > 2-3. * The magnitude of the 95% confidence interval found for BJH-pore size distributions severely impedes drawing quantitative conclusions. REFERENCES [1] S. Brunauer, P.H. Emmett, E. Teller, Adsorption of gases in multimolecular layers, Journal of the American Chemical Society, 60 (1938) 309-319. [2] E.P. Barrett, L.G. Joyner, P.P. Halenda, The Determination of Pore Volume and Area Distributions in Porous Substances. I. Computations from Nitrogen Isotherms, Journal of the American Chemical Society, 73 (1951) 373-380.
    Microporous and Mesoporous Materials 11/2014; 200:199–215. · 3.21 Impact Factor
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    ABSTRACT: Composites incorporating two-dimensional nanostructures within polymeric matrices have potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of freestanding nanosheets has proved challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometre lateral dimensions and nanometre thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increase in the separation selectivity with pressure. As revealed by tomographic focused ion beam scanning electron microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared with isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications.
    Nature Material 11/2014; · 36.43 Impact Factor
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    ABSTRACT: Graphical abstract Figure optionsDownload full-size imageDownload as PowerPoint slide
    Microporous and Mesoporous Materials 10/2014; 197:268–277. · 3.21 Impact Factor
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    ABSTRACT: Functionalization of metal–organic frameworks results in higher hydrogen uptakes owing to stronger hydrogen–host interactions. However, it has not been studied whether a given functional group acts on existing adsorption sites (linker or metal) or introduces new ones. In this work, the effect of two types of functional groups on MIL-101 (Cr) is analyzed. Thermal-desorption spectroscopy reveals that the −Br ligand increases the secondary building unit’s hydrogen affinity, while the −NH2 functional group introduces new hydrogen adsorption sites. In addition, a subsequent introduction of −Br and −NH2 ligands on the linker results in the highest hydrogen-store interaction energy on the cationic nodes. The latter is attributed to a push-and-pull effect of the linkers.
    The Journal of Physical Chemistry C 07/2014; 118(34):19572-19579. · 4.84 Impact Factor
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    ABSTRACT: Several Al-based MOFs of the CAU family have been investigated for application in adsorption driven allocation of heat and cold. The special water adsorption behaviour of CAU-10-H makes it ideal for application in adsorption driven heat pumps and chillers. For increased performance, CAU-10-H crystals have been grown directly on both γ-alumina and metallic aluminium. Crystal growth on these surfaces can be controlled by the addition of acids.
    CrystEngComm 07/2014; · 3.86 Impact Factor
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    ABSTRACT: A straightforward synthetic route to chiral metal–organic frameworks is proposed that relies on an acid–base interaction between an acid linker and a chiral primary amino acid derived diamine organocatalyst. High ee values for the aldol condensation of linear ketones and aromatic aldehydes are reported with this heterogeneous catalyst. Three consecutive catalyst reuse experiments demonstrated that the majority of the activity was preserved, as was the enantioselectivity.
    ChemCatChem 07/2014; · 5.18 Impact Factor
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    ABSTRACT: Simulation of gas adsorption in flexible porous materials is still limited by the slow progress in the development of flexible force fields. Moreover, the high computational cost of such flexible force fields may be a drawback even when they are fully developed. In this work, molecular simulations of gas adsorption and diffusion of carbon dioxide and methane in NH2-MIL-53(Al) are carried out using a linear combination of two crystallographic structures with rigid force fields. Once the interactions of carbon dioxide molecules and the bridging hydroxyls groups of the framework are optimized, an excellent match is found for simulations and experimental data for the adsorption of methane and carbon dioxide, including the stepwise uptake due to the breathing effect. In addition, diffusivities of pure components are calculated. The pore expansion by the breathing effect influences the self-diffusion mechanism and much higher diffusivities are observed at relatively high adsorbate loadings. This work demonstrates that using a rigid force field combined with a minimum number of experiments, reproduces adsorption and simulates diffusion of carbon dioxide and methane in the flexible metal-organic framework NH2-MIL-53(Al).
    Physical Chemistry Chemical Physics 06/2014; · 4.20 Impact Factor
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    ABSTRACT: In this last chapter of the book, we highlight additional aspects, also very relevant for the future application of MOFs in catalytic processes at the industrial scale, but that have not been explicitly treated in the other chapters. On one hand, we discuss the potential of (multi-functional) MOF catalysts for one-pot tandem reactions or multicomponent coupling reactions as a means of process intensification to improve the economy of the system. On the other hand, we highlight the different approaches followed for the shaping of MOF catalysts, one of the critical steps before industrial implementation.
    ChemInform 06/2014; 45(23).
  • ChemInform 05/2014; 45(20).
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    ABSTRACT: Reticular design is a highly attractive concept, but coordination chemistry around the tectonic units of metal–organic frameworks (MOFs) and additional interplay with anionic and solvent species provide for dazzling complexity that effectively rules out structure prediction. We can however study the chemistry around pre-existing clusters, and assemble novel materials correspondingly, using a priori information about the connectivity of an investigated metal cluster. Studies, often spectroscopic of nature, have in recent years solved many puzzles in MOF crystallization. The obtained knowledge opens new doors in crystal engineering, but more research on MOF coordination chemistry has to be carried out.
    ChemInform 04/2014; 45(14).
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    ABSTRACT: In this perspective, we highlight the main opportunities of metal organic frameworks (MOFs) as heterogeneous catalysts. Along with our personal view on the most promising catalytic applications, the most important issues that still need to be addressed before commercial implementation of MOF catalysis are discussed.
    ChemInform 04/2014; 45(14).
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    ABSTRACT: In situ NMR and DFT modeling demonstrate that N,N-dimethylformamide (DMF) promotes the formation of metal-organic framework NH2-MIL-101(Al). In situ NMR studies show that upon dissociation of an aluminum-coordinated aqua ligand in NH2-MOF-235(Al), DMF forms a H-Cl-DMF complex during synthesis. This reaction induces a transformation from the MOF-235 topology into the MIL-101 topology. Electronic structure density functional theory (DFT) calculations show that the use of DMF instead of water as the synthesis solvent decreases the energy gap between the kinetically favored MIL-101 and thermodynamically favored MIL-53 products. DMF therefore promotes MIL-101 topology both kinetically and thermodynamically.
    Inorganic Chemistry 01/2014; 53(2):882–887. · 4.79 Impact Factor
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    ABSTRACT: Mixed matrix membranes (MMMs) composed of metal organic framework (MOF) fillers embedded in a polymeric matrix represent a promising alternative for CO2 removal from natural gas and biogas. Here, MMMs based on NH2-MIL-53(Al) MOF and polyimide are successfully synthesized with MOF loadings up to 25 wt% and different thicknesses. At 308 K and ΔP = 3 bar, the incorporation of the MOF filler enhances CO2 permeability with respect to membranes based on the neat polymer, while preserving the relatively high separation factor. The rate of solvent evaporation after membrane casting proves key for the final configuration and dispersion of the MOF in the membrane. Fast solvent removal favours the contraction of the MOF structure to its narrow pore framework configuration, resulting in enhanced separation factor and, particularly, CO2 permeability. The study reveals an excellent filler-polymer contact, with ca. 0.11% void volume fraction, for membranes based on the amino-functionalized MOF, even at high filler loadings (25 wt%). By providing precise and quantitative insight into key structural features at the nanoscale range, the approach provides feedback to the membrane casting process and therefore it represents an important advancement towards the rational design of mixed matrix membranes with enhanced structural features and separation performance.
    Advanced Functional Materials 01/2014; 24(2). · 10.44 Impact Factor
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    ABSTRACT: With femtosecond pump-probe spectroscopy we found for photocatalytically active NH2-MIL-125 that after photo-excitation the hole resides on -NH2. Charge transfer from the MOF to an occluded molecule capable to shuttle single charges to a reaction centre is extremely fast (< 200 fs) while charge recombination only occurs on the ns-μs time scale.
    International Conference on Ultrafast Phenomena; 01/2014

Publication Stats

2k Citations
540.00 Total Impact Points

Institutions

  • 2008–2015
    • Delft University of Technology
      • • Department of Chemical Engineering
      • • Catalysis Engineering Group
      Delft, South Holland, Netherlands
  • 2012–2014
    • University of Valencia
      • • Inorganic Chemistry
      • • Instituto de Ciencia Molecular (ICMol)
      Valenza, Valencia, Spain
  • 2013
    • Cambridge Eco
      Cambridge, England, United Kingdom
  • 2011
    • University of Zaragoza
      • Department of Chemical Engineering and Environmental Technology
      Zaragoza, Aragon, Spain
    • Brookhaven National Laboratory
      New York City, New York, United States
  • 2009–2010
    • Free University of Brussels
      • Department of Chemical Engineering (CHIS)
      Brussels, BRU, Belgium