Examinando por Autor "Horcajada, Patricia"

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Hf/porphyrin-based metal-organic framework PCN-224 for CO2 cycloaddition with epoxides
(Elsevier, 2023) Carrasco, Sergio; Orcajo, Gisela; Martínez, Fernando; Imaz, Inhar; Kavak, Safiyye; Arenas-Esteban, Daniel; Maspoch, Daniel; Bals, Sara; Calleja, Guillermo; Horcajada, Patricia
Herein, we describe for the first time the synthesis of the highly porous Hf-tetracarboxylate porphyrinbased metal-organic framework (MOF) (Hf)PCN-224(M) (M ¼ H2, Co2þ). (Hf)PCN-224(H2) was easily and efficiently prepared following a simple microwave-assisted procedure with good yields (56e67%; spacetime yields: 1100e1270 kg m3 $day1 ), high crystallinity and phase purity by using trifluoromethanesulfonic acid and benzoic acid as modulators in less than 30 min. By simply introducing a preliminary step (10 min), 5,10,15,20-(tetra-4-carboxyphenyl)porphyrin linker (TCPP) was quantitatively metalated with Co2þ without additional purification and/or time consuming protection/deprotection steps to further obtain (Hf)PCN-224(Co). (Hf)PCN-224(Co) was then tested as catalyst in CO2 cycloaddition reaction with different epoxides to yield cyclic carbonates, showing the best catalytic performance described to date compared to other PCNs, under mild conditions (1 bar CO2, room temperature, 18 e24 h). Twelve epoxides were tested, obtaining from moderate to excellent conversions (35e96%). Moreover, this reaction was gram scaled-up (x50) without significant loss of yield to cyclic carbonates. (Hf)PCN-224(Co) maintained its integrity and crystallinity even after 8 consecutive runs, and poisoning was efficiently reverted by a simple thermal treatment (175 C, 6 h), fully recovering the initial catalytic activity.
Improving the Water Resistance of Bi-Based Perovskite-Inspired Materials for Vapor-Phase Photocatalytic Overall Water Splitting
(Wiley, 2024-06-23) Chacón-García, Antonio J.; Baldovi, Herme G.; Pols, Mike; Tao, Shuxia; Calero, Sofia; Navalón, Sergio; Vitorica-Yrezabal, Iñigo J.; Rodríguez-Diéguez, Antonio; García, Hermenegildo; Horcajada, Patricia; Pérez, Yolanda
Lead halide perovskites are well known for their exceptional photophysical and electronic properties, which have placed them at the forefront of challenging optoelectronic applications and solar-to-fuel conversion. However, their air/water instability, combined with their toxicity, is still a critical problem that has slowed down their commercialization. In this sense, bismuth-based halide derivatives attract much interest as a potentially safer, air-stable alternative. Herein, a novel Bi-based perovskite-inspired material, IEF-19 (IEF stands for IMDEA Energy Framework), which contains a bulky aromatic cation (1,5-diammonium naphthalene), is prepared. Additionally, an N-alkylation strategy is successfully employed to achieve four water-stable perovskite-inspired materials, which contains diammonium naphthalene cations that are tetra-alkylated by methyl, ethyl, propyl, and butyl groups. Moreover, computational studies are performed to gain a deeper understanding of the intrinsic structural stability and affinity of water molecules for Bi-based perovskite-inspired materials. Importantly, the air- and water-stable IEF-19-Et (i.e., stable at least 12 months under ambient conditions and 3 weeks in contact with water) is found to be an active photocatalyst for vapor-phase overall water splitting in the absence of any sacrificial agent under both ultraviolet–visible or simulated sunlight irradiation. This material exhibits an estimated apparent quantum yield of 0.08% at 400 nm, partially explained by its adequate energy band level diagram
Scaling-Up Microwave-Assisted Synthesis of Highly Defective Pd@UiO-66-NH2 Catalysts for Selective Olefin Hydrogenation under Ambient Conditions
(American Chemical Society, 2024-04-26) Guerrero, Raúl M.; Lemir, Ignacio D.; Carrasco, Sergio; Fernández-Ruiz, Carlos; Kavak, Safiyye; Pizarro, Patricia; Serrano, David P.; Bals, Sara; Horcajada, Patricia; Pérez, Yolanda
The need to develop green and cost-effective industrial catalytic processes has led to growing interest in preparing more robust, efficient, and selective heterogeneous catalysts at a large scale. In this regard, microwave-assisted synthesis is a fast method for fabricating heterogeneous catalysts (including metal oxides, zeolites, metal–organic frameworks, and supported metal nanoparticles) with enhanced catalytic properties, enabling synthesis scale-up. Herein, the synthesis of nanosized UiO-66-NH2 was optimized via a microwave-assisted hydrothermal method to obtain defective matrices essential for the stabilization of metal nanoparticles, promoting catalytically active sites for hydrogenation reactions (760 kg·m–3·day–1 space time yield, STY). Then, this protocol was scaled up in a multimodal microwave reactor, reaching 86% yield (ca. 1 g, 1450 kg·m–3·day–1 STY) in only 30 min. Afterward, Pd nanoparticles were formed in situ decorating the nanoMOF by an effective and fast microwave-assisted hydrothermal method, resulting in the formation of Pd@UiO-66-NH2 composites. Both the localization and oxidation states of Pd nanoparticles (NPs) in the MOF were achieved using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray photoelectron spectroscopy (XPS), respectively. The optimal composite, loaded with 1.7 wt % Pd, exhibited an extraordinary catalytic activity (>95% yield, 100% selectivity) under mild conditions (1 bar H2, 25 °C, 1 h reaction time), not only in the selective hydrogenation of a variety of single alkenes (1-hexene, 1-octene, 1-tridecene, cyclohexene, and tetraphenyl ethylene) but also in the conversion of a complex mixture of alkenes (i.e., 1-hexene, 1-tridecene, and anethole). The results showed a powerful interaction and synergy between the active phase (Pd NPs) and the catalytic porous scaffold (UiO-66-NH2), which are essential for the selectivity and recyclability.