Using silver exchange to achieve high uptake and selectivity for propylene/ propane separation in zeolite Y

Adsorptive separation of propylene and propane, an important step of polypropylene production, is more energy-efficient than distillation. However, the challenge lies in the design of an adsorbent which exhibits both high selectivity and uptake. Herein, we hypothesise that enhancing the propylene affinity of the adsorption sites while keeping a suitable pore size can address this challenge. To do so, we performed silver exchange of a commercial zeolite Y, thereby making the adsorbent design easily scalable. We characterised the adsorbent using analytical, spectroscopic and imaging tools, tested its equilibrium and dynamic sorption properties using volumetric and gravimetric techniques and compared its performance to those of state-of-the-art adsorbents as well as other silver-functionalised adsorbents. The silver-exchanged zeolite Y (Ag-Y) exhibited one of the best selectivity vs uptake performances reported so far. Ag-Y also displayed fast adsorption kinetics and reversible propylene sorption, making it a promising new benchmark for propylene/propane separation. Synchrotron-based pair distribution function analyses identified the silver cations’ location which confirmed that the silver sites are easily accessible to the adsorbates. This aspect can, in part, explain the propylene/propane separation performance observed. The overall design strategy proposed here to enhance sorption site affinity and maintain pore size could be extended to other adsorbents and support the deployment of adsorption technology for propylene/propane separation

Magnesium Exchanged Zirconium Metal−Organic Frameworks with Improved Detoxification Properties of Nerve Agents

UiO-66, MOF-808 and NU-1000 metal-organic frameworks exhibit a differentiated reactivity toward [Mg(OMe)2(MeOH)2]4 related to their pore accessibility. Microporous UiO-66 remains unchanged while mesoporous MOF-808 and hierarchical micro/mesoporous NU-1000 materials yield doped systems containing exposed MgZr5O2(OH)6 clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P-F and P-S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions

Material órgano-inorgánico microporoso cristalino basado en cationes alcalinotérreos, procedimiento de preparación y usos

Material órgano-inorgánico microporoso cristalino basado en cationes alcalinotérreos, procedimiento de preparación y usos. La presente invención se refiere a una familia de materiales órgano-inorgánicos microporosos cristalinos conteniendo cationes alcalinotérreos y ácidos dicarboxílicos, su procedimiento de preparación y su uso como catalizadores heterogéneos reutilizables para reacciones en química orgánica, como tamices moleculares y como absorbentes de gases y líquidos.Peer reviewedConsejo Superior de Investigaciones Científicas (España), Instituto Madrileño de Estudios Avanzados en Energía (IMDEA-ENERGÍA)A1 Solicitud de patentes con informe sobre el estado de la técnic

Dynamic calcium metal-organic framework acts as a selective organic solvent sponge

Herein, we present a Ca-based metal–organic framework named AEPF-1, which is an active and selective catalyst in olefin hydrogenation reactions. AEPF-1 exhibits a phase transition upon desorption of guest molecules. This structural transformation takes place by a crystal to crystal transformation accompanied by the loss of single-crystal integrity. Powder diffraction methods and computational studies were applied to determine the structure of the guest-free phase. This work also presents data on the exceptional adsorption behavior of this material, which is shown to be capable of separating polar from nonpolar organic solvents, and is a good candidate for selective solvent adsorption under mild conditions.This work has been supported by the Spanish MCYT Project Mat 2007-60822, CTQ 2007-28909-E/BQU, and Consolider-Ingenio CSD2006-2001. A.E.P.P. acknowledges a JAE fellowship from CSIC and Fondo Social Europeo from EU. V.A.P.O. acknowledges financial support from the MCYT in the Ramón y Cajal research program.Peer Reviewe