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Microwave (MW) heating has been applied to increase the selectivity to propylene in the oxidative dehydrogenation (ODH) of propane. The preferential heating of the solid monolith (made of SiC, a good microwave susceptor), allows working with a lower gas phase temperature, reducing the formation of undesired by-products in the gas phase via homogeneous reactions. Conversion levels of ~ 21% and selectivity to propylene up to 70% have been achieved with MW-heated straight channel monolithic reactors coated with a VMgO catalyst. These competitive values contrast with the more limited performance delivered by the same catalytic system when it is subjected to conventional heating in a fixed-bed reactor configuration, thereby corroborating the advantage of working under a significant gas–solid temperature gap to minimize the extent of homogeneous reactions. ; Financial support from the European Research Council (ERC Advanced Grant HECTOR-267626) and the Regional Government of Aragon (DGA) is gratefully acknowledged. The CIBER-BBN (initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund) is gratefully acknowledged. The synthesis of materials has been performed by the Platform of Production of Biomaterials and Nanoparticles of the NANOBIOSIS ICTS, more specifically by the Nanoparticle Synthesis Unit of the CIBER in BioEngineering, Biomaterials & Nanomedicine (CIBER-BBN).

Research in solid-gas heterogeneous catalytic processes is typically aimed toward optimization of catalyst composition to achieve a higher conversion and, especially, a higher selectivity. However, even with the most selective catalysts, an upper limit is found: Above a certain temperature, gas-phase reactions become important and their effects cannot be neglected. Here, we apply a microwave field to a catalyst-support ensemble capable of direct microwave heating (MWH). We have taken extra precautions to ensure that (i) the solid phase is free from significant hot spots and (ii) an accurate estimation of both solid and gas temperatures is obtained. MWH allows operating with a catalyst that is significantly hotter than the surrounding gas, achieving a high conversion on the catalyst while reducing undesired homogeneous reactions. We demonstrate the concept with the CO 2 -mediated oxidative dehydrogenation of isobutane, but it can be applied to any system with significant undesired homogeneous contributions. ; Financial support from the European Research Council Advanced Grant (HECTOR267626), the Regional Government of Aragon (DGA), and the MINECO and FEDER (project CTQ2015-65226) is acknowledged. ; Peer reviewed

9 figures, 1 table.-- Supplementary information available. ; Ultramicroporous carbons loaded with silver (Ag) nanoparticles were synthesised by submitting tannins to hydrothermal treatment in aqueous solutions of silver nitrate at different concentrations, followed by a pyrolysis step. The resultant materials were oxidised with dioxygen diluted in argon for removing the carbon partly coating the Ag nanoparticles and thus increasing the active metal surface area. Morphological, chemical, structural and textural characterisations were carried out in order to establish relationships between the physicochemical properties of the materials and their performances as catalysts for ethylene epoxidation. The latter reaction was increasingly promoted at higher silver content, and the efficiency of the oxidative post-treatment was evidenced. The relation between selectivity and Ag content was nonlinear, in favour of the improved availability of silver nanoparticles after the removal of the carbon coating, at constant surface area and micropore size distribution of the carbon support. A favourable effect of Ag nanoparticles agglomeration on the selectivity was suggested. ; The authors gratefully acknowledge the financial support of the CPER 2007–2013 "Structuration du Pôle de Compétitivité Fibres Grand'Est" (Competitiveness Fibre Cluster), through local (Conseil Général des Vosges), regional (Région Lorraine), national (DRRT and FNADT) and European (FEDER) funds. Part of this work was supported by CHEERS project (FEDER funds). Financial support from the Regional Government of Aragon (DGA) is gratefully acknowledged.

9 figures, 1 table.-- Supplementary information available. ; Ultramicroporous carbons loaded with silver (Ag) nanoparticles were synthesised by submitting tannins to hydrothermal treatment in aqueous solutions of silver nitrate at different concentrations, followed by a pyrolysis step. The resultant materials were oxidised with dioxygen diluted in argon for removing the carbon partly coating the Ag nanoparticles and thus increasing the active metal surface area. Morphological, chemical, structural and textural characterisations were carried out in order to establish relationships between the physicochemical properties of the materials and their performances as catalysts for ethylene epoxidation. The latter reaction was increasingly promoted at higher silver content, and the efficiency of the oxidative post-treatment was evidenced. The relation between selectivity and Ag content was nonlinear, in favour of the improved availability of silver nanoparticles after the removal of the carbon coating, at constant surface area and micropore size distribution of the carbon support. A favourable effect of Ag nanoparticles agglomeration on the selectivity was suggested. ; The authors gratefully acknowledge the financial support of the CPER 2007–2013 "Structuration du Pôle de Compétitivité Fibres Grand'Est" (Competitiveness Fibre Cluster), through local (Conseil Général des Vosges), regional (Région Lorraine), national (DRRT and FNADT) and European (FEDER) funds. Part of this work was supported by CHEERS project (FEDER funds). Financial support from the Regional Government of Aragon (DGA) is gratefully acknowledged.

The conversion of methane into higher molecular weight hydrocarbons of greater added value has emerged as one of the grand challenges of the 21st century. The non-oxidative methane dehydroaromatization (hereafter MDA) reaction is a promising methane valorisation reaction since it transforms methane into added-value aromatics and olefins, namely benzene, naphthalene and ethylene. Molybdenum-promoted ZSM-5 zeolite has proven to be one of the most effective catalysts for MDA providing a shape-selective environment for the conversion of methane into benzene. However, one of the principle disadvantages of using aluminosilicates in the presence of methane is that the catalyst suffers from rapid deactivation induced by coke formation, which ultimately leads to a decrease in activity and aromatics selectivity, making the process unsuitable for large-scale industrial applications. Better control of the metal dispersion on the surface of the aluminosilicate supports represents a crucial factor to partially suppress catalyst coking and improve stability. Here we show how different molecular polyoxomolybdate (POM) anions can be used as alternative Mo precursors to conventional Mo salts for the preparation of catalysts for the MDA reaction. Molecular dynamics simulations and experimental testing were conducted to characterize the interphase interactions between polyoxomolybdates and zeolite surfaces at the atomistic level and to evaluate the MDA performance of different POM-based catalysts supported on ZSM-5 and MCM-22, respectively. The catalysts prepared using hexamolybdate anions, [Mo6O19]2−, were found to be more active and selective towards benzene than those employing the commercial heptamolybdate, [Mo7O24]6−. The Mo loading and dispersion of MoOx species were found to be the key factors leading to enhanced catalytic stability on ZSM-5 and MCM-22-based supports for MDA where the 5% Mo6/MCM-22 catalyst provided a constant aromatics yield above 7% for more than 18 hours time-on stream operating at 700 °C with a diluted methane flow under atmospheric pressure. The zeolitic catalysts prepared with the Mo6 precursor were found to be amongst the most promising MDA catalysts in the literature and the results of this study pave the way for the selection and use of different POMs as innovative metal precursors to formulate new catalysts and further improve the MDA reaction process. ; Financial support from the European Union's Horizon 2020 Research and Innovation Programme (ADREM project – Grant Agreement No. 680777) is gratefully acknowledged. The microscopy measurements were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. The synthesis of the materials has been performed at the Platform of Production of Biomaterials and Nanoparticles of the NANOBIOSIS ICTS, more specifically at the Nanoparticle Synthesis Unit of the CIBER in BioEngineering, Biomaterials & Nanomedicine (CIBER-BBN). JMP thanks the Spanish Ministry of Science (CTQ2017-87269-P), the Generalitat de Catalunya (2017SGR629) and the URV for support. JMP also thanks the ICREA foundation for an ICREA ACADEMIA award. ; Peer reviewed

Surface-enhanced Raman scattering (SERS) is a powerful spectroscopic technique for selective detection and quantification of molecules at extremely low concentrations. However, practical SERS applications for gaseous chemicals with small cross section is still in its early stages. We herein report a plasmonic-sorbent thin-film platform with integrated Raman internal standard with outstanding SERS sensing capabilities for chemical warfare agents (CWA) simulants. The thin film is constituted of close-packed core–shell Au@Ag nanorods individually encapsulated within a ZIF-8 framework (Au@Ag@ZIF-8). While the Au@Ag nanoparticles amplify the Raman signal of molecules located near their surface, the ZIF-8 framework plays a key role in the trapping of the dimethyl methylphosphonate (DMMP) or 2-chloroethyl ethyl sulfide (CEES) from the gas phase as well as Raman internal standard. The underlying adsorption mechanism of the molecules within the ZIF-8 framework as well as the interaction between DMMP and Ag surface are investigated by computational simulations. Outstanding SERS sensing capabilities of Au@Ag@ZIF-8 thin films, in terms of response time, quantification limit, reproducibility, and recyclability, are demonstrated for dimethyl methylphosphonate (DMMP) and 2-chloroethyl ethyl sulfide (CEES), selected as CWA simulants of sarin gas and mustard gas, respectively. A limit of detection (LOD) of 0.2 ppbV is reported for DMMP. Additionally, experiments performed with portable Raman equipment detect 2.5 ppmV for DMMP in ambient air and 76 ppbV for CEES in N2, with response times of 21 and 54 s, respectively. This proof of concept opens the door for handheld SERS-based gas sensing at ultralow concentrations in practical applications, such as homeland security, critical infrastructure protection, chemical process monitoring, or personalized medicine. ; The authors are grateful for financial support from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 883390 (H2020-SU-SECU-2019 SERSing Project), Spanish State Research Agency (CTQ2016-79419-R, MAT2016-77809-R, PID2019-108660RB-I00 and PID2019-108954RB-I00), Gobierno de Aragón (T57-17R p, Feder 2014-2020 "Construyendo Europa desde Aragón"), Xunta de Galicia (GRC ED431C 2016-048, FEDER 1014-2020), and CIBER-BNN (initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions, and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund). ; Peer reviewed

This article is part of the themed collection: Editor's Choice: Single-atom and nanocluster catalysis. ; One of the hallmarks of microwave irradiation is its selective heating mechanism. In the past 30 years, alternative designs of chemical reactors have been introduced, where the microwave (MW) absorber occupies a limited reactor volume but the surrounding environment is MW transparent. This advantage results in a different heating profile or even the possibility to quickly cool down the system. Simultaneous cooling–microwave heating has been largely adopted for organic chemical transformations. However, to the best of our knowledge there are no reports of its application in the field of nanocluster synthesis. In this work, we propose an innovative one-pot procedure for the synthesis of Cu nanoclusters. The cluster nucleation was selectively MW-activated inside the pores of a highly ordered mesoporous substrate. Once the nucleation event occurred, the crystallization reaction was instantaneously quenched, precluding the growth events and favoring the production of Cu clusters with a homogenous size distribution. Herein, we demonstrated that Cu nanoclusters could be successfully adopted for radical cascade annulations of N-alkoxybenzamides, resulting in various tricyclic and tetracyclic isoquinolones, which are widely present in lots of natural products and bioactive compounds. Compared to reported homogeneous methods, supported Cu nanoclusters provide a better platform for a green, sustainable and efficient heterogeneous approach for the synthesis of tricyclic and tetracyclic isoquinolones, avoiding a variety of toxic waste/byproducts and metal contamination in the final products. ; Liangliang Song appreciates the Postdoctoral Mandate (PDM) of KU Leuven. This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement no. 721290. This publication reflects only the author's view, exempting the Community from any liability. Project website: http://cosmic-etn.eu/. LVM thanks the Hercules Foundation for supporting the purchase of the diffractometer through project AKUL/09/0035. We acknowledge the FWO [Fund for Scientific Research-Flanders (Belgium)] and the Research Council of KU Leuven (BOF) for financial support. We acknowledge the support of RUDN University Program 5-100. The microscopy works have been conducted in the Laboratorio de Microscopias Avanzadas at Instituto de Nanociencia de Aragón-Universidad de Zaragoza. Authors acknowledge the LMA-INA for offering access to their instruments and expertise. ; Peer reviewed

This article belongs to the Special Issue Microwave-Assisted Catalysis. ; Microwave-assisted heterogeneous catalysis (MHC) is gaining attention due to its exciting prospects related to selective catalyst heating, enhanced energy-efficiency, and partial inhibition of detrimental side gas-phase reactions. The induced temperature difference between the catalyst and the comparatively colder surrounding reactive atmosphere is pointed as the main factor of the process selectivity enhancement towards the products of interest in a number of hydrocarbon conversion processes. However, MHC is traditionally restricted to catalytic reactions in the absence of catalyst coking. As excellent MW-susceptors, carbon deposits represent an enormous drawback of the MHC technology, being main responsible of long-term process malfunctions. This work addresses the potentials and limitations of MHC for such processes affected by coking (MHCC). It also intends to evaluate the use of different catalyst and reactor configurations to overcome heating stability problems derived from the undesired coke deposits. The concept of long-term MHCC operation has been experimentally tested/applied to for the methane non-oxidative coupling reaction at 700 °C on Mo/ZSM-5@SiC structured catalysts. Preliminary process scalability tests suggest that a 6-fold power input increases the processing of methane flow by 150 times under the same controlled temperature and spatial velocity conditions. This finding paves the way for the implementation of high-capacity MHCC processes at up-scaled facilities. ; This research was funded by the European Union's Horizon 2020 Research and Innovation Programme (ADREM project–Grant Agreement no. 680777) and the APC have been waived by the journal. ; Peer reviewed

Lung disease is one of the most important causes of high morbidity in preterm infants. In this work, we study a simple and easy to fabricate microfluidic device that demonstrates a great potential for blood oxygenation. A meander type architecture with double side vertical membrane arrangement has been selected as reference model to investigate the oxygenation process. The design criteria for the fabricated devices has been to maximize the oxygen saturation level while ensuring the physiological blood flow in order to avoid thrombus formation and channel blockage during operation. A mathematical model for the oxygen transfer has been developed and validated by the experimental study. The obtained results demonstrate that blood was successfully oxygenated up to approximately 98% of O-2 saturation and that the oxygen transfer rate at 1 mL/min blood flow rate was approximately 92 mL/minm(2). Finally, a sensitivity analysis of the key parameters, i.e. size of the channel, oxygen concentration in the gas phase and oxygen permeation properties of the membrane, is carried out to discuss the performance limits and to settle the guidelines for future developments. ; The authors would like to acknowledge the financial support from the Government of Aragón and the Education, Audiovisual and Culture Executive Agency (EU-EACEA) within the EUDIME - 'Erasmus Mundus Doctorate in Membrane Engineering' program (FPA 2011-0014, SGA 2012-1719, http://eudime.unical.it). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011 financed by the Instituto de Salud Carlos III with the assistance of the European Regional Development Fund. Authors acknowledge the LMA-INA for offering access to their instruments and expertise.

In this work, we study alveolar-like microfluidic devices with a horizontal membrane arrangement that demonstrate a great potential as small-scale blood oxygenator. The design criteria for the fabricated devices were to maximize the oxygen saturation level and minimize liquid chamber volume while ensuring the physiological blood flow in order to avoid thrombus formation and channel blockage during operation. The liquid chamber architecture was iteratively modified upon analysis of the fluid dynamics by computer modelling. Accordingly, two alveolar type architectures were fabricated, Alveolar Design 1 (AD1) and Alveolar Design 2 (AD2), and evaluated for oxygenation of sheep blood. The attained O2 transfer rate at 1 mL/min of blood flow rate for both devices was rather similar: 123 mL·min-1 ·m-2 and 127 mL·min-1 ·m-2 for AD1 and AD2 microfluidic devices, respectively. Among the studied, AD2 type geometry would lead to the lowest pressure drop and shear stress value upon implementation in a scaled microfluidic artificial lung (µAL) to satisfy oxygenation requirements of a 2.0 kg neonate. ; Government of Aragon and the Education, Audiovisual and Culture Executive Agency (EU-EACEA) within the EUDIME – 'Erasmus Mundus Doctorate in Membrane Engineering' program (FPA 2011-0014, SGA 2012-1719, http://eudime.unical.it). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011 financed by the Instituto de Salud Carlos III with the assistance of the European Regional Development Fund.

Sergio Santoro acknowledges the European Commission for the financial support: The Education, Audiovisual and Culture Executive Agency (EU-EACEA) within the EUDIME Erasmus Mundus Doctorate in Membrane Engineering program (FPA 2011-0014, SGA 2012-1719, Edition II, http://eudime.unical.it). Ivan Moreno acknowledges the PhD grant from the Aragon Government, DGA, reference B008/12. ; Membrane distillation (MD) has recently gained considerable attention as a valid process for the production of fresh-water due to its ability to exploit low grade waste heat for operation and to ensure a nearly feed concentration-independent production of high-purity distillate. Limitations have been related to polarization phenomena negatively affecting the thermal efficiency of the process and, as a consequence, its productivity. Several theoretical models have been developed to predict the impact of the operating conditions of the process on the thermal polarization, but there is a lack of experimental validation. In this study, electrospun nanofiber membranes (ENMs) made of Poly(vinylidene fluoride) (PVDF) and doped with (1, 10-phenanthroline) ruthenium (II) Ru(phen) 3 were tested at different operating conditions (i.e., temperature and velocity of the feed) in direct contact membrane distillation (DCMD). The temperature sensitive luminophore, Ru(phen) 3 , allowed the on-line and non-invasive mapping of the temperature at the membrane surface during the process and the experimental evaluation of the effect of the temperature and velocity of the feed on the thermal polarization. ; publishersversion ; published