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Scientific Papers in SCI



2023


Química de Superficies y Catálisis

Unravelling the CO2 capture and conversion mechanism of a NiRu-Na2O switchable dual-function material in various CO2 utilisation reactions

Merkouri, LP; Martin-Espejo, JL; Bobadilla, LF; Odriozola, JA; Penkova, A; Reina, T; Duyar, MS
Journal of Materials Chemistry A, 11 (2023) 13209-13216

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Time-resolved operando DRIFTS-MS was performed to elucidate the CO2 capture and conversion mechanisms of a NiRuNa/CeAl DFM in CO2 methanation, reverse water-gas shift, and dry reforming of methane. CO2 was captured mainly in the form of carbonyls and bidentate carbonates, and a spillover mechanism occurred to obtain the desired products.


May, 2023 | DOI: 10.1039/d3ta01892j

Química de Superficies y Catálisis

MIL-100(Fe)-derived catalysts for CO2 conversion via low- and high-temperature reverse water-gas shift reaction

Loe, JG; Pena, AP; Espejo, JLM; Bobadilla, LF; Reina, TR; Pastor-Perez, L
Heliyon, 9 (2023) e16070

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Fe-derived catalysts were synthesized by the pyrolysis of MIL-100 (Fe) metal-organic framework (MOF) and evaluated in the reverse water-gas shift (RWGS) reaction. The addition of Rh as a dopant by in-situ incorporation during the synthesis and wet impregnation was also considered. Our characterization data showed that the main active phase was a mixture of & alpha;-Fe, Fe3C, and Fe3O4 in all the catalysts evaluated. Additionally, small Rh loading leads to a decrease in the particle size in the active phase. Despite all three catalysts showing commendable CO selectivity levels, the C@Fe* catalyst showed the most promising performance at a temperature below 500 degrees C, attributed to the in-situ incorporation of Rh during the synthesis. Overall, this work showcases a strategy for designing novel Fe MOF-derived catalysts for RWGS reaction, opening new research opportunities for CO2 utilization schemes.


May, 2023 | DOI: 10.1016/j.heliyon.2023.e16070

Nanotecnología en Superficies y Plasma

Optical monitoring of detergent pollutants in greywater

Lahoz, F; de Armas-Rillo, S; Hernandez-Rodriguez, C; Gil-Rostra, J; Yubero, F
Optics Express, 31 (2023) 15227-15238

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Large amount of wastewater is produced by washing machines and dishwashers, which are used in a daily basis. This domestic wastewater generated in households or office buildings (also called greywater) is drained directly to the drainpipes without differentiation from that with fecal contamination from toilets. Detergents are arguably the pollutants most frequently found in greywater from home appliances. Their concentrations vary in the successive stages in a wash cycle, which could be taken into account in a rational design of home appliances wastewater management. Analytical chemistry procedures are commonly used to determine the pollutant content in wastewater. They require collecting samples and their transport to properly equipped laboratories, which hampers real time wastewater management. In this paper, optofluidic devices based on planar Fabry-Perot microresonators operating in transmission mode in the visible and near infrared spectral ranges have been studied to determine the concentration of five brands of soap dissolved in water. It is found that the spectral positions of the optical resonances redshift when the soap concentration increases in the corresponding solutions. Experimental calibration curves of the optofluidic device were used to determine the soap concentration of wastewater from the successive stages of a washing machine wash cycle either loaded with garments or unloaded. Interestingly, the analysis of the optical sensor indicated that the greywater from the last water discharge of the wash cycle could be reused for gardening or agriculture. The integration of this kind of microfluidic devices into the home appliances design could lead to reduce our hydric environmental impact.


May, 2023 | DOI: 10.1364/OE.466194

Materiales Ópticos Multifuncionales

Modeling Weakly Scattering Random Media: A Tool to Resolve the Internal Structure of Nanoporous Materials

Jimenez-Solano, A; Miranda-Munoz, JM; Carretero-Palacios, S; Miguez, H
Advanced Photonics Research, 4 (2023) 5

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Nanoporous media scatter a small fraction of the light propagating through them, even if pore sizes are significantly smaller than the characteristic visible wavelengths. The disordered spatial modulation of the refractive index at the few or few tens of nanometers length scale, resulting from the presence of randomly distributed air bubbles or solid aggregates within a continuous solid background, gives rise to these weak scattering effects. However, standard theoretical approaches to describe this kind of media use effective medium approximations that do not account for diffuse, ballistic, and specular components. Herein, all spectral components and the angular distribution of the scattered light are captured through optical modeling. A Monte Carlo approach, combining scattering Mie theory and Fresnel equations, implemented within a genetic algorithm, allows us to decode the void and aggregate size distribution and hence the internal structure of a nanocrystalline titania (TiO2) film chosen as a paradigmatic example. The approach allows to generically describe the scattering properties of nanoporous materials which, as shown herein, may be used to decipher their internal structure from the fitting of their far-optical field properties.


May, 2023 | DOI: 10.1002/adpr.202200267

Química de Superficies y Catálisis

Carbon Capture Enhancement by Water-Based Nanofluids in a Hollow Fiber Membrane Contactor

Yuan, CT; Pan, Z; Wang, Y; Baena-Moreno, FM; Constantinou, A; Zhang, Z
Energy Technology, 11 (2023) 2300254

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Nanoparticles are being used in the CO2 solvents to improve the capture performance. Herein, a 2D model is proposed to study the CO2 capture performance from a gaseous mixture using a hollow fiber membrane contactor (HFMC). Both water-based nanofluids of carbon nanotubes (CNT) and SiO2 are deployed as the carbon absorbents. It is verified that Brownian motion and grazing effect are the major reasons to enhance the mass transfer of nanofluids. The simulation findings show that the modeling data conform well with the experimental studies. The root-mean-square errors for SiO2 nanofluid and CNT nanofluid are 2.37% and 2.56%, respectively. When the amounts of nanoparticles increase between 0.02 and 0.06 wt%, CO2 capture efficiencies of SiO2 and CNT nanofluids increase by 7.92% and 13.17%, respectively. Also, the CNT nanofluid has a better capture performance than the SiO2 nanofluid. Furthermore, research is conducted into how membrane characteristics affect HFMC performance. It is indicated that increasing the membrane porosity and decreasing the membrane tortuosity have a positive impact on the capture efficiency. This work demonstrates the potentials in the use of nanoparticles in CO2 solvents and provides a solid theoretical basis for nanofluids to significantly enhance gas absorption.


May, 2023 | DOI: 10.1002/ente.202300254

 

 

 

 

 

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