A5009991442- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- Electrocatalysts for Energy Conversion
- Advancements in Battery Materials
- Catalysts for Methane Reforming
- Advanced Photocatalysis Techniques
- Copper-based nanomaterials and applications
- Electron and X-Ray Spectroscopy Techniques
- Porphyrin and Phthalocyanine Chemistry
- Spectroscopy and Quantum Chemical Studies
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Nanomaterials for catalytic reactions
- nanoparticles nucleation surface interactions
- CO2 Reduction Techniques and Catalysts
- Gas Sensing Nanomaterials and Sensors
- Nanocluster Synthesis and Applications
- Advanced Chemical Physics Studies
- Advanced Battery Materials and Technologies
- Catalysis and Hydrodesulfurization Studies
- Graphene research and applications
- Supramolecular Chemistry and Complexes
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Battery Technologies Research
- ZnO doping and properties
ALBA Synchrotron (Spain)
2016-2025
Lawrence Berkeley National Laboratory
2012-2024
National University of Río Cuarto
2024
Universidad del Rosario
2023
Centre for Research on Ecology and Forestry Applications
2020
Universitat de Barcelona
2005-2010
Sunlight plays a critical role in the development of emerging sustainable energy conversion and storage technologies. Light-induced CO2 reduction by artificial photosynthesis is one cornerstones to produce renewable fuels environmentally friendly chemicals. Interface interactions between plasmonic metal nanoparticles semiconductors exhibit improved photoactivities under wide range solar spectrum. However, photo-induced charge transfer processes their influence on photocatalysis with these...
In situ soft X-ray absorption spectroscopy (XAS) was employed to study the adsorption and dissociation of carbon monoxide molecules on cobalt nanoparticles with sizes ranging from 4 15 nm. The majority CO adsorb molecularly surface nanoparticles, but some undergo dissociative adsorption, leading oxide species nanoparticles. We found that tendency depends critically size Co Indeed, dissociate much more efficiently larger (15 nm) than smaller particles (4 nm). further observed a strong...
Supported nanoparticles make the reaction faster Several techniques now allow surface structures used as catalysts to be probed during exposure reactive gases, opposed under vacuum conditions. Divins et al. near-ambient-pressure x-ray photoelectron spectroscopy compare effect of gases on unsupported palladium-rhodium versus ones a reducible cerium oxide support. For ethanol with steam produce hydrogen, supported were more and less prone reduction rearrangement. Science , this issue p. 620
The preferential CO oxidation (CO-PROX) reaction is paramount for the purification of reformate H2-rich streams, where CuO/CeO2 catalysts show promising opportunities. This work sheds light on lattice oxygen recovery mechanism during CO-PROX reaction, which critical to guarantee both good activity and selectivity, but that yet be well understood. Particularly, in situ Raman spectroscopy reveals vacancies ceria do not form significant amounts until advanced degrees, whereas pulse O2 isotopic...
Stir it up! Comparison of the evolution with time J-aggregates title porphyrin in stagnant and vortex-stirred solutions showed that chiral-sign selection is due to action hydrodynamic gradients (shear flows) on particle folding. Brownian dynamics (stagnant solution) result irregularly folded mesophases, whereas (vortex stirring) lead long-order folding formation helical ribbons (see picture). Amphiphilic anionic porphyrins self-assemble spontaneous breaking mirror symmetry.1 In case 2...
Ruthenium nanoparticles with a core–shell structure formed by core of metallic ruthenium and shell carbide have been synthesized mild easy hydrothermal treatment. The dual composition the determined synchrotron X-ray photoelectron spectroscopy (XPS), near-edge absorption fine (NEXAFS) analysis, transmission electron microscopy (TEM) imaging. According to depth profile XPS diffraction (XRD) species predominate in inner layers material, being located on upper surface layers. carbon catalysts...
The solid electrolyte interphase (SEI) that forms on Li-ion battery anodes is critical to their long-term performance, however observing SEI formation processes at the buried electrode-electrolyte interface a significant challenge. Here we show operando soft X-ray absorption spectroscopy in total electron yield mode can resolve chemical evolution of during electrochemical cell, with nm-scale sensitivity. O, F, and Si K-edge spectra, acquired as function potential, reveal when key reactions...
synchrotron radiation-based techniques are a precious tool in battery research, as they enable the detection of metastable intermediates and ensure characterization under realistic cycling conditions. However, do not come exempt risks. The interaction between radiation samples, particularly within an active electrochemical cell, can induce relevant effects at irradiated spot, potentially jeopardizing experiment's reliability biasing data interpretation. With aim contributing to this ongoing...
The structure and composition of core–shell CuCo nanoparticles were found to change as a result cleaning pretreatments when exposed syngas (CO + H2) at atmospheric pressure. In situ X-ray absorption photoelectron spectroscopies revealed the oxidation state particles well presence adsorbates under syngas. Transmission electron microscopy was used for ex analysis shape, elemental composition, after reaction. original hollow alloy pretreatment by in pure O2 reduction H2. After 30 min exposure...
The structure of the meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS4) J-aggregates could be determined by X-ray and electron diffraction methods. A sheet-like architecture reveals relationship between chirality, optics shapes meso 4-sulfonatophenyl- phenyl-substituted porphyrins. H4TPPS4 belongs to chiral space group P21 includes four porphyrin molecules in its unit cell. intermolecular stabilization zwitterionic units hydrogen bonding electrostatic interactions positively charged central...
The steam reforming of ethanol (ESR) has been studied by near ambient pressure XPS (NAP-XPS), extended X-ray absorption fine structure (EXAFS), and edge (XANES) under in situ conditions the ALBA synchrotron facility at 200–580 °C S/C = 3 over different cobalt-based catalysts that showed catalytic performances: Co3[Si2O5]2(OH)2 (Co-talc), [Co2Mg4Al2(OH)16]CO3·4H2O (Co-hydrotalcite shortened to Co-HT) calcined 550 °C, Co3O4 (Co-spinel). Both Co-spinel Co-talc yield a greater or lesser degree...
The strong metal–support interaction (SMSI) effect plays a central role in catalysis by decreasing the catalytic activity or even improving it some specific cases. In spite of intense research, detailed description SMSI CeO2-based catalysts is still missing. this work, CuxNi1–x/CeO2 (0 < x 1) nanoparticles were exposed to reduction treatment H2 atmosphere followed an oxidation CO2 atmosphere, both at 500 °C, and studied using state-of-the-art techniques (in situ time-resolved X-ray...
Abstract Removing soot is one of the most important challenges in minimizing impact combustion engines on environment. Catalysts based CeO 2 have proved suitable to oxidize owing their capacity store and release oxygen easily while maintaining structural integrity, although mode operation a complex environment involving two solid phases (catalyst soot) gas phase (oxygen) not yet fully understood. Herein, we provide study surface/subsurface ceria–soot ceria–zirconia–soot mixtures under...
Electrochemistry and surface water redox reactions on Pb(Zr<sub>0.2</sub>,Ti<sub>0.8</sub>)O<sub>3</sub> ferroelectric thin films as a function of polarization external electric field, studied by AP-XPS KPFM.
Unveiling surface adsorbates under atmospheric conditions and in water redox reactions on TiO<sub>2</sub> terminated surfaces ferroelectric oxides, as studied by AP-XPS.
Abstract Efficiently treating methane emissions in transportation remains a challenge. Here, we investigate palladium and platinum mono- bimetallic ceria-supported catalysts synthesized by mechanical milling traditional impregnation for total oxidation under dry wet conditions, reproducing those present the exhaust of natural gas vehicles. By applying toolkit situ synchrotron techniques (X-ray diffraction, X-ray absorption ambient pressure photoelectron spectroscopies), together with...
The formation of helical self-assembled fibres by a C(3) symmetric molecule incorporating three tetrathiafulvalene units is shown to be influenced dramatically the processing conditions, leading variety different chiral forms, including unprecedented croissants.
Surface segregation and restructuring in size-selected CuNi nanoparticles were investigated via near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) at various temperatures different gas environments. Particularly focus structural morphological changes occurring under CO2 hydrogenation conditions the presence of carbon monoxide (CO) reactant mixture. Nickel surface was observed when only CO present as adsorbate. The trend is inverted a reaction mixture consisting CO2, H2, CO,...
Self-assembled nanostructures such as those formed by peptide amphiphiles (PAs) are of great interest in biological and pharmacological applications. Herein, a simple widely applicable chemical modification, urea motif, was included the PA's molecular structure to stabilize virtue intermolecular hydrogen bonds. Since amino acid residue nearest lipid tail is most relevant for stability, we decided include modification at that position. We prepared four groups molecules (13 PAs all), with...