B18-Core EXAFS
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Open Access
Abstract: Metal nanoparticles are widely considered for heterogeneous catalysis due to their high atomic efficiency and tunable active microenvironment, but their specific functional tendencies are still unclear. Here, we report that a Rh@ZrO2/NC catalyst with only 0.1 wt% Rh exhibits exceptional catalytic performance and high selectivity (p-nitroacetophenone conversion-98.6 %, p-aminoacetophenone selectivity-100 %, r-56.4 molp-nitroacetophenone/(molRh·min)) towards the hydrogenation of the -NO2 group in nitroarene to -NH2. This is because the interaction between Rh species and “ZrO2-N” results in significant hydrogen spillover in the catalyst, as supported by DFT calculations. Extensive characterizations from TG, DTG, NAP-XPS, in-situ Raman spectroscopy, in-situ DRIFT spectroscopy and DFT calculations further confirm the adsorption, activation and dissociation of hydrogen on Rh nanoparticles. The H* species migrate readily over ZrO2-NC, to facilitate the catalytic activity and selectivity for the hydrogenation of nitroarene. This study presents a new approach to develop highly efficient and selective metal nanoparticle-catalysts for cost-effective hydrogenation reactions.
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Dec 2025
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B16-Test Beamline
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Diamond Proposal Number(s):
[33032]
Open Access
Abstract: This study presents the first demonstration of the use of X-ray diffraction (XRD) to quantify the radial or transverse deformation in Hexcel IM7 PolyAcryloNitrile (PAN)-based carbon fibres at temperatures as low as 200 K (-70 °C). The Coefficient of Thermal Expansion (CTE) is a critical design parameter that needs to be precisely quantified for the next generation of carbon fibre-based Liquid Hydrogen (
) storage tanks for net-zero aviation. This variable quantitatively describes the thermal mismatch between the fibre and the resin that is the driver for microcracking and tank leakage. However, quantification of the CTE of the fibres is experimentally challenging. The results provide unique insights, indicating that the microscopic transverse CTE of the fibre (
) is equal to 26.2 × 10-6 K-1 and is governed by van der Waals forces, similar to those in the basal c-axis (out-of-plane) direction of graphite and the radial direction of multi-wall carbon nanotubes. Taking into account the microcrack-induced relaxation effect reported in polycrystalline graphite, the macroscopic fibre transverse CTE was determined to be 7.86 × 10-6 K-1. XRD data were also collected on Hexcel IM7/8552 Uni-directional (UD) and Quasi-isotropic (QI) composite laminates to investigate the influence of the interaction of the resin matrix with the fibre lattice and the stacking sequence on the development of thermal fibre lattice strain. In the UD laminate, the presence of resin induces an additional transverse strain in the fibres as a result of resin contraction during cooling, leading to the development of a compressive strain in the fibre direction. This behaviour was found to be in good agreement with numerical simulations, with a 13 % error at the lowest measured temperature. In contrast, the fibres in the QI configuration were reinforced in the transverse direction, effectively mitigating the influence of resin contraction. These CTE values, insights, and resulting models are essential for multi-scale modelling, design and certification of carbon fibre composite
tanks that are required to achieve net-zero aviation.
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Oct 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[32708]
Open Access
Abstract: BCC superalloys are a promising class of high-temperature materials with a wide range of lattice misfit values, ranging from near-zero to ∼8 %. Analogous to nickel superalloys, lattice misfit combined with elastic anisotropy dictates precipitate morphology (spherical, cuboidal, plate/needle-like), coarsening kinetics, strengthening mechanisms, and microstructure evolution, making misfit control critical for tailoring microstructural stability and creep resistance. However, misfit characterisation, especially at high temperatures, is still in its infancy to establish its links with mechanical properties. This perspective emphasises three aspects of BCC superalloys: representative misfit-driven microstructures and temperature-dependent misfit evolution, state-of-the-art diffraction techniques for high-temperature misfit quantification, and machine learning frameworks to accelerate alloy design involving misfit. By consolidating diverse misfit data and advanced characterisation/modelling strategies, we outline strategies to bridge computational and experimental gaps, advocating for physics-informed models and high-throughput techniques to design next-generation BCC superalloys and motivate systematic studies on the misfit-property relationship in this nascent material class.
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Oct 2025
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B16-Test Beamline
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Diamond Proposal Number(s):
[30528]
Open Access
Abstract: This paper demonstrates a new approach that exploits both lattice strain mapping via Wide Angle X-ray Scattering (WAXS) and Digital Volume Correlation (DVC) of Computed Tomography (CT) to understand the material response at different length scales in Carbon Fibre Reinforced Polymers (CFRPs) under in-situ loading, a phenomenon of substantial importance for the modelling, design, and certification of composite structures. WAXS gives insight into fibre lattice strain, while DVC provides sub-laminate response in the CFRP. A detailed numerical simulation was also developed to compare with these novel experimental methods. This approach is the first demonstration that the strain within the crystalline regions of the fibre is distinct from the sub-laminate behaviour, with up to 80 % and 36 % differences in the longitudinal and transverse directions, respectively, as a result of the complex microstructure of the fibres. An improved understanding of composite behaviour is fundamental to understanding how strain accommodation leads to structural failure, providing routes to refine part rejection criteria and reduce the environmental impact of this increasingly widespread material class.
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Oct 2025
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B18-Core EXAFS
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Aysun Ipek
Paksoy
,
Luis Francisco
Bobadilla
,
Rubén
Blay-Roger
,
Loukia-Pantzechroula
Merkouri
,
Victor
López-Flores
,
Claude
Coppex
,
Jelena
Jelic
,
Felix
Studt
,
Tomas
Ramirez Reina
,
José Antonio
Odriozola
,
Melis Seher
Duyar
Diamond Proposal Number(s):
[29271]
Abstract: This study reports a dual function material (DFM) composed entirely of non-precious metals for methanol production (13.8 μmol/g material) at ambient pressure from passively captured CO2 from the air. While state of the art carbon capture and utilisation (CCU) processes rely on expensive CO2 capture systems and a high-pressure catalytic reactor for methanol synthesis, this Ni-Ga-Ca DFM can be an enabler for significant energy efficiency gains in methanol synthesis from CO2 through the direct utilisation of dilute emissions and substantially lower operating pressures. Using operando DRIFT spectroscopy coupled with density functional theory, XAFS, XRD, and TEM-HAADF, a combination of Ni-Ga intermetallic species and their oxides are identified as the active sites. During cyclic operation a shift in selectivity towards methane is observed, which is associated with dynamic restructuring of the DFM. Guided by mechanistic and structural understanding, a synthesis strategy is developed to enhance cyclic stability by mitigating dealloying and Ni particle agglomeration. It is indicated that cyclic stability can be achieved by strengthening the Ni-Ga-Ca interaction, however, there remains a gradual shift in selectivity towards methane which highlights the need for further material optimisation.
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Sep 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[33667]
Open Access
Abstract: Refractory high entropy alloys have gained significant interest over the past decade as promising candidates for high-strength applications, particularly at high temperatures. However, achieving ductility and workability at room temperature remains a challenge for large-scale manufacturing and applications. This study explores the design and characterisation of a novel RHEA with low density, high ductility, and high strength at room temperature. High-throughput screening and experimental validation identified a non-equiatomic composition, Zr35Ti35Nb20V5Al5 (at%), which exhibits a room-temperature yield strength of 1030 MPa, 11% tensile strain to failure, and a low density of 6 g/cm3. The alloy's grain size was refined to <20 μm through rolling and recrystallisation, bypassing traditional high-temperature homogenisation while avoiding microsegregation. The tailored Zr35Ti35Nb20V5Al5 RHEA demonstrates a new design approach and processing route, opening applications in next-generation nuclear and aerospace technologies.
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Aug 2025
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I08-1-Soft X-ray Ptychography
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Abstract: The scales of butterflies display a vast array of vivid colors. However, the exact mechanisms behind these colours are not yet fully understood. Butterfly scales consist of intricate nanostructures that in- teract with light through interference, diffraction, and scattering. Additionally, the nanostructures on butterfly scales vary in pigment density across different species.
A combination of 'pigment effects' and ‘structural effects’ gives rise to the vivid colors observed on a butterfly’s wings. Variations in pigment density have been correlated with specific nanostructures. However, the interplay between pigmentation and nanostructures - how they influence each other - remains largely unexplored. Hence, our work aims to perform a detailed examination of the distribution of various matrix components within butterfly scales, leading to a deeper understanding of not only their colour, but also their role in guiding nano- structure growth.
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Jul 2025
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Accelerator Physics
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Younes
Chahid
,
Carolyn
Atkins
,
Stephen
Hodbod
,
John
Robinson
,
Xia
Liu
,
Stephen
Watson
,
Maia
Jones
,
Mark
Cliffe
,
Dayo
Ogunkanmi
,
Richard
Kotlewski
,
Lee
Chapman
,
Scott
Beamish
,
Jorge
Linde Cerezo
,
Thomas
Wearing
,
Ahmad
Baroutaji
,
Arun
Arjunan
,
Chantal
Fowler
,
Paul
Vivian
Open Access
Abstract: Many of the 70 synchrotron facilities worldwide are undergoing upgrades to their infrastructure to meet a growing demand for increased beam brightness with nanometre-level stability. These upgrades increase the mechanical and thermal challenges faced by beamline components, creating opportunities to apply novel methodologies and manufacturing processes to optimize hardware performance and beam accuracy. Absorbers are important beamline components that rely on water-cooled channels to absorb thermal energy from excess light caused by synchrotron radiation or photon beams created by insertion devices, all within a limited volume, to protect downstream equipment and ensure safe, reliable operation. Additive manufacturing (AM) has been shown to meet criteria relevant to synchrotron environments like leak tightness and vacuum compatibility. However, there is a research gap on the heat transfer and pressure drop impact of different AM conformal cooling channel geometries, as well as the print quality of AM copper parts using low-power infrared lasers and their compliance with absorber requirements. In this study, an intermediate model of a Diamond Light Source photon absorber was optimized to incorporate AM conformal cooling channels, leading to two concept designs named `Horizontal' and `Coil'. When compared with the baseline design, the lightweight Horizontal concept performed the best in this study, with simulations showing a maximum temperature drop of 11%, a calculated pressure drop reduction of 82%, a mass reduction of 86%, and the consolidation of 21 individually brazed pipes into a single manifold. The AM print quality and compliance with the synchrotron environment was examined by producing custom benchmark artefacts and measuring their surface roughness, dimensional accuracy and porosity levels, which are characteristics that can affect heat absorption, structural integrity, thermal conductivity and vacuum performance. The study demonstrates the benefits and addresses outstanding challenges in reducing thermal fatigue, as well as the size, vibrations and energy consumption of AM absorbers.
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Jul 2025
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B18-Core EXAFS
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Diamond Proposal Number(s):
[40577]
Open Access
Abstract: Mitigating climate change is one of the biggest challenges of today's society. The most direct way to achieve this goal is to capture and use CO2 as a source of energy and chemicals. This work, inspired by previous publications focused on homogeneous catalysis, proposes the transformation of the easy-to-prepare CO2 derivatives dialkylureas into C1 chemicals using Ru-MOFs as heterogeneous catalysts. This choice is due to (i) the well-known ability of Ru to catalyze hydrogenation reactions and (ii) that Ru-complexes were the pioneer homogenous catalyst in converting CO2 into an added-value C1 chemical, methanol. Apart from the already reported MOF Ru-HKUST-1, we have prepared a new Ru-MOF material, denoted Ru-BTC, analogous to the semiamorphous Fe-BTC. It has been found by XAS that Ru-BTC and Ru-HKUST-1 have different metal environment and oxidation states: only 3+ in Ru-BTC, a 50:50 mixture of 2+ and 3+ in Ru-HKUST-1. Both Ru-MOFs catalyzed the hydrogenation of N,N’-dimethylurea under relatively mild conditions, giving methane as the main product. Ru-BTC was particularly efficient: 67 % conversion and 96 % selectivity to CH4 at 150 ºC and 30 bars of H2 using a Ru/dimethylurea weight ratio of 1 %. Ru-MOFs were also able to transform CO2 into CH4, again being Ru-BTC the most effective catalyst, but giving much poorer selectivity to CH4. Ru-MOFs, particularly Ru-BTC, were damaged under reaction conditions, but no significant Ru leaching was observed.
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Jul 2025
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I16-Materials and Magnetism
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Diamond Proposal Number(s):
[36376]
Open Access
Abstract: We report the results of synchrotron Bragg Coherent X-ray Diffraction Imaging (BCDI) experiments to investigate domain formation in a micron-sized magnetite crystal undergoing the Verwey transition at low temperature. A strong splitting of the measured 311 Bragg reflection was observed in the low-temperature phase, indicating the formation of domains. BCDI revealed pronounced strain distributions, characterized by a clear layered stripe domain structure in real space. Stripes were seen only along the [001] crystallographic direction, normal to the substrate surface direction, breaking the symmetry of the cubic high-temperature phase. It is argued that other domain directions were suppressed by the sample mounting orientation. More surprisingly, only a single domain orientation was observed, suggesting an additional symmetry-breaking influence originating from the shape of the crystal. Gaining insight into how thermal effects induce the formation of layered or striped phases offers a valuable framework for understanding the development of mesoscopic domains and strain patterns in functional materials.
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Jul 2025
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