A5008063541- X-ray Diffraction in Crystallography
- Catalytic Processes in Materials Science
- Crystallization and Solubility Studies
- Catalysis and Oxidation Reactions
- Electrocatalysts for Energy Conversion
- Metal-Organic Frameworks: Synthesis and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Metal complexes synthesis and properties
- Electron and X-Ray Spectroscopy Techniques
- Machine Learning in Materials Science
- CO2 Reduction Techniques and Catalysts
- Fuel Cells and Related Materials
- Copper-based nanomaterials and applications
- Lanthanide and Transition Metal Complexes
- Magnetism in coordination complexes
- Advanced Photocatalysis Techniques
- Catalysis and Hydrodesulfurization Studies
- Diamond and Carbon-based Materials Research
- Porphyrin and Phthalocyanine Chemistry
- Nanomaterials for catalytic reactions
- Chalcogenide Semiconductor Thin Films
- Electrochemical Analysis and Applications
- Quantum Dots Synthesis And Properties
- DNA and Nucleic Acid Chemistry
- Advanced Battery Materials and Technologies
Diamond Light Source
2015-2024
The University of Texas at Austin
2023
University of York
2022
Didcot Community Hospital
2014-2021
Rutherford Appleton Laboratory
2020
Research Complex at Harwell
2020
Chilton Medical Center
2018-2019
Mary Lyon Centre at MRC Harwell
2018
University of Turin
2009-2014
National Interuniversity Consortium of Materials Science and Technology
2010-2013
The recently discovered UiO-66/67/68 class of isostructural metallorganic frameworks (MOFs) [J. H. Cavka et al. J. Am. Chem. Soc., 2008, 130, 13850] has attracted great interest because its remarkable stability at high temperatures, pressures and in the presence different solvents, acids bases [L. Valenzano Mater., 2011, 23, 1700]. UiO-66 is obtained by connecting Zr6O4(OH)4 inorganic cornerstones with 1,4-benzene-dicarboxylate (BDC) as linker resulting a cubic MOF, which already been...
Abstract The design of active and durable catalysts for the H 2 O/O interconversion is one major challenges electrocatalysis renewable energy. oxygen evolution reaction (OER) catalyzed by SrRuO 3 with low potentials (ca. 1.35 V RHE ), but catalyst’s durability insufficient. Here we show that Na doping enhances both activity in acid media. DFT reveals whereas binds intermediates too strongly, ~0.125 leads to nearly optimal OER activity. increases oxidation state Ru, thereby displacing...
The carbon-carbon coupling via electrochemical reduction of carbon dioxide represents the biggest challenge for using this route as platform chemicals synthesis. Here we show that nanostructured iron (III) oxyhydroxide on nitrogen-doped enables high Faraday efficiency (97.4%) and selectivity to acetic acid (61%) at very-low potential (-0.5 V vs silver/silver chloride). Using a combination electron microscopy, operando X-ray spectroscopy techniques density functional theory simulations,...
High-resolution synchrotron radiation x-ray powder diffraction (HR-XRPD) combined with Hf $L$3-edge extended absorption fine structure allowed us to determine the of a Hf-UiO-66 metal-organic framework (MOF) showing that it is isoreticular Zr-UiO-66 MOF [Cavka et al., J. Am. Chem. Soc. 130, 13850 (2008).]. Thermal gravimetric measurements (coupled mass spectroscopy) and temperature-dependent XRPD proved high thermal stability MOF. The Langmuir surface area (849 m${}^{2}/$g) UiO-66 neutron...
Proton exchange membrane water electrolysis is a promising technology to produce green hydrogen from renewables, as it can efficiently achieve high current densities. Lowering iridium amount in oxygen evolution reaction electrocatalysts critical for achieving cost-effective production of hydrogen. In this work, we develop catalysts Ir double perovskites. Sr
The production of green hydrogen in water electrolyzers is limited by the oxygen evolution reaction (OER). State-of-the-art electrocatalysts are based on Ir. Ru a suitable alternative provided their performance improved. Here we show that low-Ru-content pyrochlores (R2MnRuO7, R = Y, Tb and Dy) display high activity durability for OER acidic media. Y2MnRuO7 most stable catalyst, displaying 1.5 V at 10 mA cm-2 40 h, or 5000 cycles up to 1.7 V. Computational experimental results owed sites...
We report a careful characterization of the interaction NH3 with Cu(II) sites [Cu2C4O8] paddle-wheel cornerstone HKUST-1 metallorganic framework, also known as Cu3(BTC)2. The general picture emerging from combining XRPD, EXAFS, XANES, mid- and far-IR, DRUV–vis, EPR techniques is that presence traces water has relevant consequences on effect ammonia MOF framework. adsorption dry system results in strong chemisorption distorts keeping crystallinity material. Perturbation observed upon...
Abstract Copper nanoparticles (Cu‐NPs) have a wide range of applications as heterogeneous catalysts. In this study, novel green biosynthesis route for producing Cu‐NPs using the metal‐reducing bacterium, Shewanella oneidensis is demonstrated. Thin section transmission electron microscopy shows that are predominantly intracellular and present in typical size 20–40 nm. Serial block‐face scanning demonstrates well‐dispersed across 3D structure cells. X‐ray absorption near‐edge spectroscopy...
Abstract Supported atomic metal sites have discrete molecular orbitals. Precise control over the energies of these is key to achieving novel reaction pathways with superior selectivity. Here, we achieve selective oxygen (O 2 ) activation by utilising a framework cerium (Ce) cations reduce energy 3 d orbitals isolated copper (Cu) sites. Operando X-ray absorption spectroscopy, electron paramagnetic resonance and density-functional theory simulations are used demonstrate that [Cu(I)O ] 3− site...
During the last three decades low dimensional systems attracted increasing interest both from fundamental and technological point of view due to their unique physical chemical properties.X-ray Absorption Spectroscopy (XAS) is a powerful tool for characterization such kind systems, owing its selectivity high sensitivity in interatomic distances determination.Moreover this technique can simultaneously provide information on electronic local structural properties nanomaterials, significantly...
The oxygen evolution reaction (OER) is crucial to future energy systems based on water electrolysis. Iridium oxides are promising catalysts due their resistance corrosion under acidic and oxidizing conditions. Highly active iridium (oxy)hydroxides prepared using alkali metal bases transform into low activity rutile IrO2 at elevated temperatures (>350 °C) during catalyst/electrode preparation. Depending the residual amount of metals, we now show that this transformation can result in either...
As a fascinating innovative class of effective catalysts for hydrogen evolution reaction (HER), transition-metal tellurides have emerged as attractive materials, but they are still suffering from their intrinsic activity practical applications. Defect engineering constitutes promising strategy to optimize the electronic configuration catalyst and further improve HER activity. Herein, we present successful fabrication PdTe2-based with three different types vacancies (d-PdTex), including...
Abstract Electrochemical hydrogen peroxide (H 2 O ) production (EHPP) via a two-electron oxygen reduction reaction (2e - ORR) provides promising alternative to replace the energy-intensive anthraquinone process. M-N-C electrocatalysts, which consist of atomically dispersed transition metals and nitrogen-doped carbon, have demonstrated considerable EHPP efficiency. However, their full potential, particularly regarding correlation between structural configurations performances in neutral...
Sustainable technologies require both renewable feedstocks and catalysts that are able to direct their conversion specific products. We establish a structure-activity relationship for the aqueous phase reforming of glycerol over 2% Pt/Al2O3 catalysts, whereby reaction pathway can be controlled produce either hydrogen or 1,2-propanediol as main product. Using colloidal synthesis method, reduction temperature was altered Pt nanoparticle supported on Al2O3 with varying particle size. The...
Three recurring hypotheses are often used to explain the effect of non-thermal plasmas (NTPs) on NTP catalytic hybrid reactions; namely, modification or heating catalyst creation new reaction pathways by plasma-produced species. NTP-assisted methane (CH4 ) oxidation over Pd/Al2 O3 was investigated direct monitoring X-ray absorption fine structure catalyst, coupled with end-of-pipe mass spectrometry. This in situ study revealed that did not undergo any significant structural changes under...
Platinum single-site catalysts (SSCs) are a promising technology for the production of hydrogen from clean energy sources. They have high activity and maximal platinum-atom utilization. However, bonding environment platinum during operation is poorly understood. In this work, we present mechanistic study SSCs using operando, synchrotron-X-ray absorption spectroscopy. We synthesize an atomically dispersed complex with aniline chloride ligands onto graphene characterize it ex-situ electron...
Given the challenging task of constructing an efficient nitrogen reduction reaction (NRR) electrocatalyst with enhanced ambient condition performance, properties such as high specific surface area, fast electron transfer, and design catalyst constitute a group key factors to be taken into consideration guarantee outstanding catalytic performance durability. Thereof, this work investigates contribution 2D/2D heterojunction interface between MoS2 reduced graphene oxide (rGO) on...
The new complex [Ru(bpy)(4AP)4]2+ (1), where bpy = 2,2′-bipyridine and 4AP 4-aminopyridine, undergoes selective photodissociation of two 4APs upon light excitation the metal−ligand-to-ligand charge-transfer (MLLCT) band at 510 nm. photoproducts reaction are mer-[Ru(bpy)(4AP)3(H2O)]2+ (2a) trans-(4AP)[Ru(bpy)(4AP)2(H2O)2]2+ (3a). Photodissociation occurs in consecutive steps with quantum yields φ1 (6.1 ± 1.0) × 10−3 φ2 (1.7 0.1) 10−4, respectively. Complex 1 was characterized by combined...
The understanding, at the atomic level, of role played by additives (dopants or promoters) in chemistry an industrial catalyst is a very complex and difficult task. We succeeded this goal for ethylene oxychlorination (CuCl(2)/gamma-Al(2)O(3)), used to produce dichloroethane, key intermediate polyvinyl chloride (PVC). Among most both fluid fixed beds technologies (LiCl, KCl, CsCl, MgCl(2), LaCl(3), CeCl(4)) we have been able highlight that forming reaction conditions mixed phase with CuCl(2),...
Low-temperature topochemical reduction of the cation disordered perovskite phase SrFe0.5Ru0.5O3 with CaH2 yields infinite layer SrFe0.5Ru0.5O2. Thermogravimetric and X-ray absorption data confirm transition metal oxidation states as SrFe0.52+Ru0.52+O2; thus, title is first reported observation Ru2+ centers in an extended oxide phase. DFT calculations reveal that, while square-planar Fe2+ adopt a high-spin S = 2 electronic configuration, cations have intermediate 1 configuration. This...
The use of AuPd nanoparticles in catalysis is widespread, with the activity being attributed to their precise structural properties. We demonstrate restructuring under CO oxidation conditions using a combined XAFS/DRIFTS approach. fresh catalyst exhibits PdO islands at surface nanoparticles, which are reduced reaction conditions, process observed via both DRIFTS and Pd K-edge XAFS measurements. From EXAFS analysis alone were have Au rich core an outer region intimately mixed atoms. This...
This manuscript presents the current status and technical details of Spectroscopy Village at Diamond Light Source. The is formed four beamlines: I18, B18, I20-Scanning I20-EDE. village provides UK community with local access to a hard X-ray microprobe, quick-scanning multi-purpose XAS beamline, high-intensity beamline for absorption spectroscopy dilute samples emission spectroscopy, an energy-dispersive extended fine-structure beamline. optics I20-scanning I20-EDE are detailed; moreover,...
EXAFS and XANES experiments were used to assess decavanadate interplay with actin, in both the globular polymerized forms, under different conditions of pH, temperature, ionic strength, presence ATP. This approach allowed us simultaneously probe, for first time, all vanadium species present system. It was established that interacts G-actin, triggering a protein conformational reorientation induces oxidation cysteine core residues oxidovanadium (VIV) formation. The local environment...
The nature and evolution of FeNxCy moieties in Fe/C/N catalysts has been studied by analysing Fe N environments. TEM Fe-XAS reveal the presence FeNx Fe3C particles fresh catalyst. NEXAFS reveals two groups (Fe)NxCy ensembles, namely (Fe)Nx-pyridinic (Fe)Nx-pyrrolic. architecture ensembles their during ORR analysed XAS, NEXAFS, identical locations TEM. NxCy, species are partially removed ORR, resulting formation Fe2O3 Fe3O4 with different morphologies. process is more severe acid electrolyte...