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Dr. Reyes Mallada
Department of Chemical and Environmental Engineering, University of Zaragoza, Edif. I+D, Campus Río Ebro, Despacho: 7.2.09, C/ Mariano Esquillor s/n, 50018-Zaragoza, Spain

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0 microreactors
0 Microwave heating
0 synthesis inorganic porous materials
0 zeolite layers
0 zeolite membranes

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Journal article
Published: 21 July 2021 in Membranes
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Protein crystallization still remains mostly an empirical science, as the production of crystals with the required quality for X-ray analysis is dependent on the intensive screening of the best protein crystallization and crystal’s derivatization conditions. Herein, this demanding step was addressed by the development of a high-throughput and low-budget microfluidic platform consisting of an ion exchange membrane (117 Nafion® membrane) sandwiched between a channel layer (stripping phase compartment) and a wells layer (feed phase compartment) forming 75 independent micro-contactors. This microfluidic device allows for a simultaneous and independent screening of multiple protein crystallization and crystal derivatization conditions, using Hen Egg White Lysozyme (HEWL) as the model protein and Hg2+ as the derivatizing agent. This microdevice offers well-regulated crystallization and subsequent crystal derivatization processes based on the controlled transport of water and ions provided by the 117 Nafion® membrane. Diffusion coefficients of water and the derivatizing agent (Hg2+) were evaluated, showing the positive influence of the protein drop volume on the number of crystals and crystal size. This microfluidic system allowed for crystals with good structural stability and high X-ray diffraction quality and, thus, it is regarded as an efficient tool that may contribute to the enhancement of the proteins’ crystals structural resolution.

ACS Style

M. Polino; H. Rho; M. Pina; R. Mallada; A. Carvalho; M. Romão; Isabel Coelhoso; J. Gardeniers; J. Crespo; Carla Portugal. Protein Crystallization in a Microfluidic Contactor with Nafion®117 Membranes. Membranes 2021, 11, 549 .

AMA Style

M. Polino, H. Rho, M. Pina, R. Mallada, A. Carvalho, M. Romão, Isabel Coelhoso, J. Gardeniers, J. Crespo, Carla Portugal. Protein Crystallization in a Microfluidic Contactor with Nafion®117 Membranes. Membranes. 2021; 11 (8):549.

Chicago/Turabian Style

M. Polino; H. Rho; M. Pina; R. Mallada; A. Carvalho; M. Romão; Isabel Coelhoso; J. Gardeniers; J. Crespo; Carla Portugal. 2021. "Protein Crystallization in a Microfluidic Contactor with Nafion®117 Membranes." Membranes 11, no. 8: 549.

Research article
Published: 27 May 2021 in ACS Sensors
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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 [email protected] nanorods individually encapsulated within a ZIF-8 framework ([email protected]@ZIF-8). While the [email protected] 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 [email protected]@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.

ACS Style

Marta Lafuente; Sarah De Marchi; Miguel Urbiztondo; Isabel Pastoriza-Santos; Ignacio Pérez-Juste; Jesús Santamaría; Reyes Mallada; María Pina. Plasmonic MOF Thin Films with Raman Internal Standard for Fast and Ultrasensitive SERS Detection of Chemical Warfare Agents in Ambient Air. ACS Sensors 2021, 6, 2241 -2251.

AMA Style

Marta Lafuente, Sarah De Marchi, Miguel Urbiztondo, Isabel Pastoriza-Santos, Ignacio Pérez-Juste, Jesús Santamaría, Reyes Mallada, María Pina. Plasmonic MOF Thin Films with Raman Internal Standard for Fast and Ultrasensitive SERS Detection of Chemical Warfare Agents in Ambient Air. ACS Sensors. 2021; 6 (6):2241-2251.

Chicago/Turabian Style

Marta Lafuente; Sarah De Marchi; Miguel Urbiztondo; Isabel Pastoriza-Santos; Ignacio Pérez-Juste; Jesús Santamaría; Reyes Mallada; María Pina. 2021. "Plasmonic MOF Thin Films with Raman Internal Standard for Fast and Ultrasensitive SERS Detection of Chemical Warfare Agents in Ambient Air." ACS Sensors 6, no. 6: 2241-2251.

Journal article
Published: 18 April 2021 in Catalysis Today
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Microwave-assisted gas-phase conversion on structured catalysts is emerging as a promising process intensification technology in the field of heterogeneous catalysis. The combination of selective heating and structured catalytic materials induces a temperature difference between the heated catalytic sample and the surrounding void regions to avoid non-selective gas-phase reactions. This operational principle allowed inhibiting thermal cracking in alkane dehydrogenation processes as well as retarding catalyst deactivation by coking in methane dehydroaromatization (MDA) processes. However, its effectiveness has not been reported so far out of the laboratory scale conditions. This work addresses the scaling of the microwave-assisted MDA process from lab scale experiments to a scaled-up configuration capable of stable operation with a 150-fold higher feeding rate. The scaling-up potential and main obstacles to overcome for this technology are critically discussed. In addition, a techno-economic assessment of the MW-MDA process is presented. The catalytic activity was kept for seven consecutive reaction cycles, i.e. 35 h MW-MDA, prior to a progressive decay due to permanent deactivation caused by zeolite dealumination and active metal loss. The scaled set-up operated for up to 295 consecutive hours under unmanned operation conducting 4 -h MDA-regeneration cycles on Mo/[email protected] monoliths and resulting in 125-fold increase of converted methane and a 450-fold increase of benzene (0.17 LC6H6/h) in comparison with the laboratory scale tests. Scaled set-up experiments were run using only a 6-fold microwave input power, thus, highlighting the non-linearity between energy consumption and scaling factor for this technology and the importance of microwave cavity design.

ACS Style

I. Julian; C.M. Pedersen; A.B. Jensen; A.K. Baden; J.L. Hueso; A.V. Friderichsen; H. Birkedal; R. Mallada; J. Santamaria. From bench scale to pilot plant: A 150x scaled-up configuration of a microwave-driven structured reactor for methane dehydroaromatization. Catalysis Today 2021, 1 .

AMA Style

I. Julian, C.M. Pedersen, A.B. Jensen, A.K. Baden, J.L. Hueso, A.V. Friderichsen, H. Birkedal, R. Mallada, J. Santamaria. From bench scale to pilot plant: A 150x scaled-up configuration of a microwave-driven structured reactor for methane dehydroaromatization. Catalysis Today. 2021; ():1.

Chicago/Turabian Style

I. Julian; C.M. Pedersen; A.B. Jensen; A.K. Baden; J.L. Hueso; A.V. Friderichsen; H. Birkedal; R. Mallada; J. Santamaria. 2021. "From bench scale to pilot plant: A 150x scaled-up configuration of a microwave-driven structured reactor for methane dehydroaromatization." Catalysis Today , no. : 1.

Journal article
Published: 02 February 2021 in Membranes
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In this study, we report the impact of the magnetic field on protein permeability through magnetic-responsive, block copolymer, nanocomposite membranes with hydrophilic and hydrophobic characters. The hydrophilic nanocomposite membranes were composed of spherical polymeric nanoparticles (NPs) synthesized through polymerization-induced self-assembly (PISA) with iron oxide NPs coated with quaternized poly(2-dimethylamino)ethyl methacrylate. The hydrophobic nanocomposite membranes were prepared via nonsolvent-induced phase separation (NIPS) containing poly (methacrylic acid) and meso-2,3-dimercaptosuccinic acid-coated superparamagnetic nanoparticles (SPNPs). The permeation experiments were carried out using bovine serum albumin (BSA) as the model solute, in the absence of the magnetic field and under permanent and cyclic magnetic field conditions OFF/ON (strategy 1) and ON/OFF (strategy 2). It was observed that the magnetic field led to a lower reduction in the permeate fluxes of magnetic-responsive membranes during BSA permeation, regardless of the magnetic field strategy used, than that obtained in the absence of the magnetic field. Nevertheless, a comparative analysis of the effect caused by the two cyclic magnetic field strategies showed that strategy 2 allowed for a lower reduction of the original permeate fluxes during BSA permeation and higher protein sieving coefficients. Overall, these novel magneto-responsive block copolymer nanocomposite membranes proved to be competent in mitigating biofouling phenomena in bioseparation processes.

ACS Style

Lakshmeesha Upadhyaya; Mona Semsarilar; Damien Quemener; Rodrigo Fernández-Pacheco; Gema Martinez; Isabel Coelhoso; Suzana Nunes; João Crespo; Reyes Mallada; Carla Portugal. Block Copolymer-Based Magnetic Mixed Matrix Membranes—Effect of Magnetic Field on Protein Permeation and Membrane Fouling. Membranes 2021, 11, 105 .

AMA Style

Lakshmeesha Upadhyaya, Mona Semsarilar, Damien Quemener, Rodrigo Fernández-Pacheco, Gema Martinez, Isabel Coelhoso, Suzana Nunes, João Crespo, Reyes Mallada, Carla Portugal. Block Copolymer-Based Magnetic Mixed Matrix Membranes—Effect of Magnetic Field on Protein Permeation and Membrane Fouling. Membranes. 2021; 11 (2):105.

Chicago/Turabian Style

Lakshmeesha Upadhyaya; Mona Semsarilar; Damien Quemener; Rodrigo Fernández-Pacheco; Gema Martinez; Isabel Coelhoso; Suzana Nunes; João Crespo; Reyes Mallada; Carla Portugal. 2021. "Block Copolymer-Based Magnetic Mixed Matrix Membranes—Effect of Magnetic Field on Protein Permeation and Membrane Fouling." Membranes 11, no. 2: 105.

Research article
Published: 09 July 2020 in ACS Applied Materials & Interfaces
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We present a simple, versatile and low-cost approach for the preparation of SERS-active regions within a microfluidic channel 50 cm in length. The approach involves the UV-light-driven formation of polyoxometalate-decorated gold nanostructures, [email protected] (POM: H3PW12O40 (PW) and H3PMo12O40 (PMo)), that self-assemble in situ on the surface of the PDMS microchannels without any extra functionalization procedure. The fabricated LoCs were characterized by SEM, UV-Vis, Raman, XRD and XPS techniques. The SERS activity of the resulting [email protected]–coated lab-on-a-chip (LoC) devices was evaluated in both static and flow conditions using Rhodamine R6G. The SERS response of [email protected]–based LoCs was found superior to [email protected] counterparts and outstanding when compared to reported data on [email protected] nanocomposites. We demonstrate the potentialities of both [email protected]–coated LoCs as analytical platforms for real time detection of the organophosphorous pesticide Paraoxon-methyl at 10-6 M concentration level.

ACS Style

Marta Lafuente; Ismael Pellejero; Alberto Clemente; Miguel A. Urbiztondo; Reyes Mallada; Santiago Reinoso; María P. Pina; Luis M. Gandía. In Situ Synthesis of SERS-Active [email protected] Nanostructures in a Microfluidic Device for Real-Time Detection of Water Pollutants. ACS Applied Materials & Interfaces 2020, 12, 36458 -36467.

AMA Style

Marta Lafuente, Ismael Pellejero, Alberto Clemente, Miguel A. Urbiztondo, Reyes Mallada, Santiago Reinoso, María P. Pina, Luis M. Gandía. In Situ Synthesis of SERS-Active [email protected] Nanostructures in a Microfluidic Device for Real-Time Detection of Water Pollutants. ACS Applied Materials & Interfaces. 2020; 12 (32):36458-36467.

Chicago/Turabian Style

Marta Lafuente; Ismael Pellejero; Alberto Clemente; Miguel A. Urbiztondo; Reyes Mallada; Santiago Reinoso; María P. Pina; Luis M. Gandía. 2020. "In Situ Synthesis of SERS-Active [email protected] Nanostructures in a Microfluidic Device for Real-Time Detection of Water Pollutants." ACS Applied Materials & Interfaces 12, no. 32: 36458-36467.

Journal article
Published: 28 April 2020 in Catalysis Today
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Despite the continuous developments in the synthesis of noble metal nanoparticles, the uniformity of particle size distribution still represents a critical aspect. A fast and homogeneous nucleation is a key requirement to achieve a monodisperse particle size distribution and in this scenario, the application of alternative energy sources may constitute a winning strategy for the development of highly active nanocatalysts with unique properties. Here we present several approaches to control the synthesis of Ag nanoparticles stabilized by an anionic template, and the results evidence the advantages of adopting unconventional heating techniques such as microwave heating. The fast and selective electromagnetic heating strongly reduced the nucleation and growth times, impacting on the homogeneity of the resulting particle size distribution. In this work, we have carried out the microwave-assisted synthesis of Ag nanoparticles and the resulting nanoparticles were compared to those synthesized under conventional heating using an oil bath, showing that the differences in temperature profile and heating rates between the two synthesis pathways had a clear effect on the size distribution of the resulting nanoparticles as well as on their stability under long term storage. Finally, the synthesized ultra-small Ag nanoparticles were deposited on a mesoporous substrate, reducing undesired Ostwald ripening and facilitating their reusability. This nanocatalyst was adopted for the abatement of 4-nitrophenol, a well-known carcinogenic pollutant with adverse effects on human beings and aquatic life. The catalytic results confirm the high activity of the catalyst thanks to the high dispersion achieved afforded by ultra-small Ag nanoparticles and the accessibility provided by the wide SBA-15 mesoporous channels.

ACS Style

Roberta Manno; Victor Sebastian; Silvia Irusta; Reyes Mallada; Jesús Santamaria. Ultra-Small Silver Nanoparticles Immobilized in Mesoporous SBA-15. Microwave-Assisted Synthesis and Catalytic Activity in the 4-Nitrophenol Reduction. Catalysis Today 2020, 362, 81 -89.

AMA Style

Roberta Manno, Victor Sebastian, Silvia Irusta, Reyes Mallada, Jesús Santamaria. Ultra-Small Silver Nanoparticles Immobilized in Mesoporous SBA-15. Microwave-Assisted Synthesis and Catalytic Activity in the 4-Nitrophenol Reduction. Catalysis Today. 2020; 362 ():81-89.

Chicago/Turabian Style

Roberta Manno; Victor Sebastian; Silvia Irusta; Reyes Mallada; Jesús Santamaria. 2020. "Ultra-Small Silver Nanoparticles Immobilized in Mesoporous SBA-15. Microwave-Assisted Synthesis and Catalytic Activity in the 4-Nitrophenol Reduction." Catalysis Today 362, no. : 81-89.

Original paper
Published: 26 March 2020 in Microchimica Acta
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Surface-enhanced Raman spectroscopy (SERS) is gaining importance as an ultrasensitive analytical tool for routine high-throughput analysis of a variety of molecular compounds. One of the main challenges is the development of robust, reproducible and cost-effective SERS substrates. In this work, we study the SERS activity of 3D silver mirror-like micro-pyramid structures extended in the z-direction up to 3.7 μm (G0 type substrate) or 7.7 μm (G1 type substrate), prepared by Si-based microfabrication technologies, for trace detection of organophosphorous pesticides, using paraoxon-methyl as probe molecule. The average relative standard deviation (RSD) for the SERS intensity of the peak displayed at 1338 cm-1 recorded over a centimetre scale area of the substrate is below 13% for pesticide concentrations in the range 10-6 to 10-15 mol L-1. This data underlies the spatial uniformity of the SERS response provided by the microfabrication approach. According to finite-difference time-domain (FDTD) simulations, such remarkable feature is mainly due to the contribution on electromagnetic field enhancement of edge plasmon polaritons (EPPs), propagating along the pyramid edges where the pesticide molecules are preferentially adsorbed. Graphical

ACS Style

Marta Lafuente; Erwin J. W. Berenschot; Roald M. Tiggelaar; Sergio G. Rodrigo; Reyes Mallada; Niels R. Tas; María P. Pina. Attomolar SERS detection of organophosphorous pesticides using silver mirror-like micro-pyramids as active substrate. Microchimica Acta 2020, 187, 247 -10.

AMA Style

Marta Lafuente, Erwin J. W. Berenschot, Roald M. Tiggelaar, Sergio G. Rodrigo, Reyes Mallada, Niels R. Tas, María P. Pina. Attomolar SERS detection of organophosphorous pesticides using silver mirror-like micro-pyramids as active substrate. Microchimica Acta. 2020; 187 (4):247-10.

Chicago/Turabian Style

Marta Lafuente; Erwin J. W. Berenschot; Roald M. Tiggelaar; Sergio G. Rodrigo; Reyes Mallada; Niels R. Tas; María P. Pina. 2020. "Attomolar SERS detection of organophosphorous pesticides using silver mirror-like micro-pyramids as active substrate." Microchimica Acta 187, no. 4: 247-10.

Research article
Published: 12 March 2020 in Crystal Growth & Design
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In this work, the influence of surface topography on protein crystallization over Nafion® is investigated. Two types of Nafion® based membranes were modified by soft lithographic techniques in order to create different topographies at the micro and nano scale and subsequently tested. From the analysis of the induction time, nucleation and crystal growth rate of Trypsin from Bovine Pancreas, all the patterned Nafion® based membranes show an enhanced nucleation and crystal growth. To provide additional insight to the experimental observations, the wettability properties of the prepared samples and the ratio of the Gibbs free energy of heterogeneous nucleation to homogeneous nucleation were evaluated. The crystallization outcome results from the combined effect of both, the structural and chemical properties of the nucleant Nafion® surface.

ACS Style

M. Polino; C. A. M. Portugal; H. Le The; Roald M. Tiggelaar; J. Eijkel; J. G. Crespo; I. M. Coelhoso; M. P. Pina; R. Mallada. Enhanced Protein Crystallization on Nafion Membranes Modified by Low-Cost Surface Patterning Techniques. Crystal Growth & Design 2020, 20, 2174 -2186.

AMA Style

M. Polino, C. A. M. Portugal, H. Le The, Roald M. Tiggelaar, J. Eijkel, J. G. Crespo, I. M. Coelhoso, M. P. Pina, R. Mallada. Enhanced Protein Crystallization on Nafion Membranes Modified by Low-Cost Surface Patterning Techniques. Crystal Growth & Design. 2020; 20 (4):2174-2186.

Chicago/Turabian Style

M. Polino; C. A. M. Portugal; H. Le The; Roald M. Tiggelaar; J. Eijkel; J. G. Crespo; I. M. Coelhoso; M. P. Pina; R. Mallada. 2020. "Enhanced Protein Crystallization on Nafion Membranes Modified by Low-Cost Surface Patterning Techniques." Crystal Growth & Design 20, no. 4: 2174-2186.

Journal article
Published: 10 March 2020 in Chemical Engineering Journal
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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.

ACS Style

Adrian Ramirez; Jose L. Hueso; Reyes Mallada; Jesus Santamaria. Microwave-activated structured reactors to maximize propylene selectivity in the oxidative dehydrogenation of propane. Chemical Engineering Journal 2020, 393, 124746 .

AMA Style

Adrian Ramirez, Jose L. Hueso, Reyes Mallada, Jesus Santamaria. Microwave-activated structured reactors to maximize propylene selectivity in the oxidative dehydrogenation of propane. Chemical Engineering Journal. 2020; 393 ():124746.

Chicago/Turabian Style

Adrian Ramirez; Jose L. Hueso; Reyes Mallada; Jesus Santamaria. 2020. "Microwave-activated structured reactors to maximize propylene selectivity in the oxidative dehydrogenation of propane." Chemical Engineering Journal 393, no. : 124746.

Research article
Published: 18 February 2020 in Chemistry of Materials
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Metal nanoclusters are becoming exciting candidates as highly efficient catalysts for heterogeneous processes in view of their extraordinary surface to volume ratio and the high concentration of uncoordinated atoms that contribute to enhanced catalytic activity. For this reason, the development of accurate and reliable procedures for the synthesis of stable and supported metal nanoclusters is highly desirable. Although Ag-nanoclusters (Ag-NCs) stabilized by anion templates with a structure like Ag(n+m)m+ and a long lifetime have been widely investigated, supported clusters present significant advantages regarding their recovery and recyclability. In spite of their potential, the stabilization of clusters of precious metals on porous substrates is scarcely investigated. Herein, we present an innovative approach for the synthesis of stable Ag nanoclusters designed with the aim of achieving a strict control of key phases such as mixing, microwave heating and quenching. The catalyst was used for the activation of alkynes showing excellent activity for the formation of C-O, C-N and C-C bonds. When compared with commonly used homogenous Ag-salts, Ag-NCs enhanced the catalytic activity toward the cyclization of a wide range of substrates, thereby minimizing the metal loading and allowing the separation as well as the reuse of the catalyst for multiple cycles.

ACS Style

Roberta Manno; Prabhat Ranjan; Victor Sebastian; Reyes Mallada; Silvia Irusta; Upendra K. Sharma; Erik V. Van Der Eycken; Jesús Santamaría. Continuous Microwave-Assisted Synthesis of Silver Nanoclusters Confined in Mesoporous SBA-15: Application in Alkyne Cyclizations. Chemistry of Materials 2020, 32, 2874 -2883.

AMA Style

Roberta Manno, Prabhat Ranjan, Victor Sebastian, Reyes Mallada, Silvia Irusta, Upendra K. Sharma, Erik V. Van Der Eycken, Jesús Santamaría. Continuous Microwave-Assisted Synthesis of Silver Nanoclusters Confined in Mesoporous SBA-15: Application in Alkyne Cyclizations. Chemistry of Materials. 2020; 32 (7):2874-2883.

Chicago/Turabian Style

Roberta Manno; Prabhat Ranjan; Victor Sebastian; Reyes Mallada; Silvia Irusta; Upendra K. Sharma; Erik V. Van Der Eycken; Jesús Santamaría. 2020. "Continuous Microwave-Assisted Synthesis of Silver Nanoclusters Confined in Mesoporous SBA-15: Application in Alkyne Cyclizations." Chemistry of Materials 32, no. 7: 2874-2883.

Journal article
Published: 05 November 2019 in Applied Catalysis B: Environmental
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Natural gas is currently envisioned as a potential energy and hydrocarbon feedstock in the forthcoming years. To overcome the detrimental flaring of this natural gas and the partial release of its major component, methane, novel and more effective strategies are required. These include the development of new, efficient and seemingly stable catalysts able to rapidly convert methane into valuable feedstocks. We show a novel synthesis method of Mo/ZSM-5 based on a solvothermal synthesis under supercritical conditions and reducing atmosphere (SC-STS-E) to improve metal dispersion and enhance catalyst stability and durability during the methane dehydroaromatization (MDA) reaction. In contrast to the conventional impregnation method, SC-STS-E provides a super-high atom-like metal dispersion at the zeolite pores resulting in the most stable Mo/ZSM-5 catalyst for MDA with the highest long-term hydrocarbon yield (xCH4 = 11.6% and yC2+ = 8.9%, after 15 h on stream) among the catalysts reported in literature for this reaction.

ACS Style

Ignacio Julian; Morten B. Roedern; Jose L. Hueso; Silvia Irusta; Ane K. Baden; Reyes Mallada; Zachary Davis; Jesus Santamaria. Supercritical solvothermal synthesis under reducing conditions to increase stability and durability of Mo/ZSM-5 catalysts in methane dehydroaromatization. Applied Catalysis B: Environmental 2019, 263, 118360 .

AMA Style

Ignacio Julian, Morten B. Roedern, Jose L. Hueso, Silvia Irusta, Ane K. Baden, Reyes Mallada, Zachary Davis, Jesus Santamaria. Supercritical solvothermal synthesis under reducing conditions to increase stability and durability of Mo/ZSM-5 catalysts in methane dehydroaromatization. Applied Catalysis B: Environmental. 2019; 263 ():118360.

Chicago/Turabian Style

Ignacio Julian; Morten B. Roedern; Jose L. Hueso; Silvia Irusta; Ane K. Baden; Reyes Mallada; Zachary Davis; Jesus Santamaria. 2019. "Supercritical solvothermal synthesis under reducing conditions to increase stability and durability of Mo/ZSM-5 catalysts in methane dehydroaromatization." Applied Catalysis B: Environmental 263, no. : 118360.

Journal article
Published: 19 October 2019 in Catalysts
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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/[email protected] 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.

ACS Style

Ignacio Julian; Christoffer M. Pedersen; Kostiantyn Achkasov; Jose L. Hueso; Henrik L. Hellstern; Hugo Silva; Reyes Mallada; Zachary J. Davis; Jesus Santamaria. Overcoming Stability Problems in Microwave-Assisted Heterogeneous Catalytic Processes Affected by Catalyst Coking. Catalysts 2019, 9, 867 .

AMA Style

Ignacio Julian, Christoffer M. Pedersen, Kostiantyn Achkasov, Jose L. Hueso, Henrik L. Hellstern, Hugo Silva, Reyes Mallada, Zachary J. Davis, Jesus Santamaria. Overcoming Stability Problems in Microwave-Assisted Heterogeneous Catalytic Processes Affected by Catalyst Coking. Catalysts. 2019; 9 (10):867.

Chicago/Turabian Style

Ignacio Julian; Christoffer M. Pedersen; Kostiantyn Achkasov; Jose L. Hueso; Henrik L. Hellstern; Hugo Silva; Reyes Mallada; Zachary J. Davis; Jesus Santamaria. 2019. "Overcoming Stability Problems in Microwave-Assisted Heterogeneous Catalytic Processes Affected by Catalyst Coking." Catalysts 9, no. 10: 867.

Journal article
Published: 01 October 2019 in Catalysis Science & Technology
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Catalytic stability and overall performance enhancement for the methane dehydroaromatization process using a combination of hexamolybdate species as Mo precursors and MCM-22 as catalysts support.

ACS Style

Ignacio Julian; José L. Hueso; Nidya Lara; Albert Solé-Daurá; Josep M. Poblet; Scott George Mitchell; Reyes Mallada; Jesús Santamaría. Polyoxometalates as alternative Mo precursors for methane dehydroaromatization on Mo/ZSM-5 and Mo/MCM-22 catalysts. Catalysis Science & Technology 2019, 9, 5927 -5942.

AMA Style

Ignacio Julian, José L. Hueso, Nidya Lara, Albert Solé-Daurá, Josep M. Poblet, Scott George Mitchell, Reyes Mallada, Jesús Santamaría. Polyoxometalates as alternative Mo precursors for methane dehydroaromatization on Mo/ZSM-5 and Mo/MCM-22 catalysts. Catalysis Science & Technology. 2019; 9 (21):5927-5942.

Chicago/Turabian Style

Ignacio Julian; José L. Hueso; Nidya Lara; Albert Solé-Daurá; Josep M. Poblet; Scott George Mitchell; Reyes Mallada; Jesús Santamaría. 2019. "Polyoxometalates as alternative Mo precursors for methane dehydroaromatization on Mo/ZSM-5 and Mo/MCM-22 catalysts." Catalysis Science & Technology 9, no. 21: 5927-5942.

Journal article
Published: 23 September 2019 in Journal of Hazardous Materials
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The development of SERS substrates for chemical detection of specific analytes requires appropriate selection of plasmonic metal and the surface where it is deposited. Here we deposited Ag nanoplates on three substrates: i) conventional SiO2/Si wafer, ii) stainless steel mesh and iii) graphite foils. The SERS enhancement of the signal was studied for Rhodamine 6 G (R6 G) as common liquid phase probe molecule. We conducted a comprehensive study with λ = 532, 633 and 785 nm on all the substrates. The best substrate was investigated, at the optimum laser 785 nm, for gas phase detection of dimethyl methyl phosphonate (DMMP), simulant of the G-series nerve agents, at a concentration of 2.5 ppmV (14 mg/m3). The spectral fingerprint was clearly observed; with variations on the relative intensities of SERS Raman bands compared to bulk DMMP in liquid phase reflects the DMMP-Ag interactions. These interactions were simulated by Density Functional Theory (DFT) calculations and the simulated spectra matched with the experimental one. Finally, we were detected the characteristics DMMP fingerprint with hand-held portable equipment. These results open the way for the application of SERS technique on real scenarios where robust, light-weight, miniaturized and simple to use and cost-effective tools are required by first responders.

ACS Style

Marta Lafuente; Diego Sanz; Miguel Urbiztondo; Jesús Santamaría; María Pilar Pina; Reyes Mallada. Gas phase detection of chemical warfare agents CWAs with portable Raman. Journal of Hazardous Materials 2019, 384, 121279 .

AMA Style

Marta Lafuente, Diego Sanz, Miguel Urbiztondo, Jesús Santamaría, María Pilar Pina, Reyes Mallada. Gas phase detection of chemical warfare agents CWAs with portable Raman. Journal of Hazardous Materials. 2019; 384 ():121279.

Chicago/Turabian Style

Marta Lafuente; Diego Sanz; Miguel Urbiztondo; Jesús Santamaría; María Pilar Pina; Reyes Mallada. 2019. "Gas phase detection of chemical warfare agents CWAs with portable Raman." Journal of Hazardous Materials 384, no. : 121279.

Research article
Published: 18 June 2019 in Industrial & Engineering Chemistry Research
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The synthesis of silver nanoparticles with small average size and narrow size distribution is a requirement for applications in different fields such as antibacterial or catalysis. Previous studies of nanoparticles synthesis confirm the advantages of combining continuous flow and microwave dielectric heating, given the possibilities that arise regarding control of residence time and localized volumetric heating. In this paper, we present two experimental set-ups to perform the continuous synthesis of silver nanoparticles using microwave heating (MWH) and conventional heating (CH). Experimental and simulated data confirm a different temperature profile along the reactor, being more favorable in the case of MWH. As a result, the nanoparticles synthesized under MWH presented a synthesis yield of 54% and a narrow particle size distribution (19±4.3nm). Furthermore, MWH led to reduced wall fouling by deposition of product material and allowed fast cooling of the product stream, preventing further growth of the nanoparticles.

ACS Style

Roberta Manno; Victor Sebastian; Reyes Mallada; Jesús Santamaría. 110th Anniversary: Nucleation of Ag Nanoparticles in Helical Microfluidic Reactor. Comparison between Microwave and Conventional Heating. Industrial & Engineering Chemistry Research 2019, 58, 12702 -12711.

AMA Style

Roberta Manno, Victor Sebastian, Reyes Mallada, Jesús Santamaría. 110th Anniversary: Nucleation of Ag Nanoparticles in Helical Microfluidic Reactor. Comparison between Microwave and Conventional Heating. Industrial & Engineering Chemistry Research. 2019; 58 (28):12702-12711.

Chicago/Turabian Style

Roberta Manno; Victor Sebastian; Reyes Mallada; Jesús Santamaría. 2019. "110th Anniversary: Nucleation of Ag Nanoparticles in Helical Microfluidic Reactor. Comparison between Microwave and Conventional Heating." Industrial & Engineering Chemistry Research 58, no. 28: 12702-12711.

Journal article
Published: 25 March 2019 in Applied Thermal Engineering
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Three-dimensional mathematical model was developed for a rectangular TE10n microwave heating cavity system, working at 2.45 GHz. Energy/heat, momentum equations were solved together with Maxwell’s electromagnetic field equations using Comsol Multiphysics® simulation environment. The dielectric properties, ε' and ε'', of NaY zeolite (Si/Al=2.5) were evaluated as a function of temperature. Considering these values, the microwave heating of a porous fixed-bed made of dry NaY zeolite was simulated. Electric field distribution, axial and radial temperature profiles and temperature evolution with time were obtained. The zeolite fixed bed was heated up to 180°C in 5 minutes, with 30 W power. The fixed-bed temperature evolution under non-steady state conditions showed the same trend as the one observed experimentally with only an average deviation of 10.3%. The model was used to predict microwave heating of other materials improving energy efficiency of the microwave cavity. Furthermore, the developed model was able to predict thermal runaway for zeolites.

ACS Style

Hakan Nigar; G.S.J. Sturm; B. Garcia-Baños; F.L. Peñaranda-Foix; J.M. Catalá-Civera; R. Mallada; A. Stankiewicz; J. Santamaría. Numerical analysis of microwave heating cavity: Combining electromagnetic energy, heat transfer and fluid dynamics for a NaY zeolite fixed-bed. Applied Thermal Engineering 2019, 155, 226 -238.

AMA Style

Hakan Nigar, G.S.J. Sturm, B. Garcia-Baños, F.L. Peñaranda-Foix, J.M. Catalá-Civera, R. Mallada, A. Stankiewicz, J. Santamaría. Numerical analysis of microwave heating cavity: Combining electromagnetic energy, heat transfer and fluid dynamics for a NaY zeolite fixed-bed. Applied Thermal Engineering. 2019; 155 ():226-238.

Chicago/Turabian Style

Hakan Nigar; G.S.J. Sturm; B. Garcia-Baños; F.L. Peñaranda-Foix; J.M. Catalá-Civera; R. Mallada; A. Stankiewicz; J. Santamaría. 2019. "Numerical analysis of microwave heating cavity: Combining electromagnetic energy, heat transfer and fluid dynamics for a NaY zeolite fixed-bed." Applied Thermal Engineering 155, no. : 226-238.

Research article
Published: 15 March 2019 in Science Advances
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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 CO2-mediated oxidative dehydrogenation of isobutane, but it can be applied to any system with significant undesired homogeneous contributions.

ACS Style

A. Ramirez; J. L. Hueso; M. Abian; M. U. Alzueta; R. Mallada; J. Santamaria. Escaping undesired gas-phase chemistry: Microwave-driven selectivity enhancement in heterogeneous catalytic reactors. Science Advances 2019, 5, eaau9000 .

AMA Style

A. Ramirez, J. L. Hueso, M. Abian, M. U. Alzueta, R. Mallada, J. Santamaria. Escaping undesired gas-phase chemistry: Microwave-driven selectivity enhancement in heterogeneous catalytic reactors. Science Advances. 2019; 5 (3):eaau9000.

Chicago/Turabian Style

A. Ramirez; J. L. Hueso; M. Abian; M. U. Alzueta; R. Mallada; J. Santamaria. 2019. "Escaping undesired gas-phase chemistry: Microwave-driven selectivity enhancement in heterogeneous catalytic reactors." Science Advances 5, no. 3: eaau9000.

Journal article
Published: 12 February 2019 in Molecules
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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.

ACS Style

Sergio Santoro; Ivan Vidorreta; Isabel Coelhoso; Joao Carlos Lima; Giovanni Desiderio; Giuseppe Lombardo; Enrico Drioli; Reyes Mallada; Joao Crespo; Alessandra Criscuoli; Alberto Figoli. Experimental Evaluation of the Thermal Polarization in Direct Contact Membrane Distillation Using Electrospun Nanofiber Membranes Doped With Molecular Probes. Molecules 2019, 24, 638 .

AMA Style

Sergio Santoro, Ivan Vidorreta, Isabel Coelhoso, Joao Carlos Lima, Giovanni Desiderio, Giuseppe Lombardo, Enrico Drioli, Reyes Mallada, Joao Crespo, Alessandra Criscuoli, Alberto Figoli. Experimental Evaluation of the Thermal Polarization in Direct Contact Membrane Distillation Using Electrospun Nanofiber Membranes Doped With Molecular Probes. Molecules. 2019; 24 (3):638.

Chicago/Turabian Style

Sergio Santoro; Ivan Vidorreta; Isabel Coelhoso; Joao Carlos Lima; Giovanni Desiderio; Giuseppe Lombardo; Enrico Drioli; Reyes Mallada; Joao Crespo; Alessandra Criscuoli; Alberto Figoli. 2019. "Experimental Evaluation of the Thermal Polarization in Direct Contact Membrane Distillation Using Electrospun Nanofiber Membranes Doped With Molecular Probes." Molecules 24, no. 3: 638.

Journal article
Published: 03 October 2018 in Chemical Engineering Journal
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This work presents a highly efficient photo-reactor configuration for VOC abatement. It consists of a fluidized bed made of commercial, easy to fluidize, transparent borosilicate glass beads coated with commercial TiO2 nanoparticles (0.15 to 2.3 wt% loadings). Herein, we demonstrate that the use of high-radiance/low consumption UV-LEDs as irradiation sources with a deeper light penetration under fluidizing conditions facilitates the photocatalytic response to achieve the complete oxidation of VOCs. The role of different parameters such as catalyst loading and irradiation power have been thoroughly studied and evaluated to maximize the full combustion of n-hexane. Under the high radiance (up to 2200 mW/cm2) conditions used the bed heats significantly (up to 190 °C), although this did not have an effect on the conversions reached, which depended solely on the wavelength and power used. The productivity of the photoreactor tested and the space velocity used were around 5.25x10-2 mol/g·h and 12000 h-1 respectively.

ACS Style

Carlos J. Bueno-Alejo; Jose L. Hueso; Reyes Mallada; Ignacio Julian; Jesus Santamaria. High-radiance LED-driven fluidized bed photoreactor for the complete oxidation of n-hexane in air. Chemical Engineering Journal 2018, 358, 1363 -1370.

AMA Style

Carlos J. Bueno-Alejo, Jose L. Hueso, Reyes Mallada, Ignacio Julian, Jesus Santamaria. High-radiance LED-driven fluidized bed photoreactor for the complete oxidation of n-hexane in air. Chemical Engineering Journal. 2018; 358 ():1363-1370.

Chicago/Turabian Style

Carlos J. Bueno-Alejo; Jose L. Hueso; Reyes Mallada; Ignacio Julian; Jesus Santamaria. 2018. "High-radiance LED-driven fluidized bed photoreactor for the complete oxidation of n-hexane in air." Chemical Engineering Journal 358, no. : 1363-1370.

Journal article
Published: 05 September 2018 in Membranes
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This experimental study explores the potential of supported ionic liquid membranes (SILMs) based on protic imidazolium ionic liquids (ILs) and randomly nanoporous polybenzimidazole (PBI) supports for CH4/N2 separation. In particular, three classes of SILMs have been prepared by the infiltration of porous PBI membranes with different protic moieties: 1-H-3-methylimidazolium bis (trifluoromethane sulfonyl)imide; 1-H-3-vinylimidazolium bis(trifluoromethane sulfonyl)imide followed by in situ ultraviolet (UV) polymerization to poly[1-(3H-imidazolium)ethylene] bis(trifluoromethanesulfonyl)imide. The polymerization process has been monitored by Fourier transform infrared (FTIR) spectroscopy and the concentration of the protic entities in the SILMs has been evaluated by thermogravimetric analysis (TGA). Single gas permeability values of N2 and CH4 at 313 K, 333 K and 363 K were obtained from a series of experiments conducted in a batch gas permeance system. The results obtained were assessed in terms of the preferential cavity formation and favorable solvation of methane in the apolar domains of the protic ionic network. The most attractive behavior exhibited poly[1-(3H-imidazolium)ethylene]bis(trifluoromethanesulfonyl)imide polymeric ionic liquid (PIL) cross-linked with 1% divinylbenzene supported membranes, showing stable performance when increasing the upstream pressure. The CH4/N2 permselectivity value of 2.1 with CH4 permeability of 156 Barrer at 363 K suggests that the transport mechanism of the as-prepared SILMs is solubility-dominated.

ACS Style

Parashuram Kallem; Christophe Charmette; Martin Drobek; Anne Julbe; Reyes Mallada; Maria Pilar Pina. Exploring the Gas-Permeation Properties of Proton-Conducting Membranes Based on Protic Imidazolium Ionic Liquids: Application in Natural Gas Processing. Membranes 2018, 8, 75 .

AMA Style

Parashuram Kallem, Christophe Charmette, Martin Drobek, Anne Julbe, Reyes Mallada, Maria Pilar Pina. Exploring the Gas-Permeation Properties of Proton-Conducting Membranes Based on Protic Imidazolium Ionic Liquids: Application in Natural Gas Processing. Membranes. 2018; 8 (3):75.

Chicago/Turabian Style

Parashuram Kallem; Christophe Charmette; Martin Drobek; Anne Julbe; Reyes Mallada; Maria Pilar Pina. 2018. "Exploring the Gas-Permeation Properties of Proton-Conducting Membranes Based on Protic Imidazolium Ionic Liquids: Application in Natural Gas Processing." Membranes 8, no. 3: 75.