B18-Core EXAFS
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Diamond Proposal Number(s):
[34632]
Open Access
Abstract: Carbon dioxide (CO2) hydrogenation represents a central route for sustainable fuel production and carbon recycling, yet its efficiency is critically dependent on the structural and electronic properties of the catalyst. In practical heterogeneous systems prepared by conventional wet-chemical methods, a distribution of active sites, ranging from atomically dispersed species to subnanometric clusters and nanoparticles, typically coexist in the final catalyst. Here, we investigate how support defect engineering governs this distribution in Ru/TiO2 catalysts with varying metal loadings and oxidative pre-treatments. Comprehensive spectroscopic and imaging analyses, including XPS, HR-STEM, and XAS established a clear correlation between Ru structure and catalytic behavior. Critically low Ru loadings (0.2 wt%) induced a transition from metallic nanoparticles to highly dispersed and single atom species, while oxidative pretreatment generated RuO2 like domains. A fraction of isolated Ru atoms persisted, particularly on defect-rich TiO2, where oxygen vacancies act as anchoring sites, improving stability under redox conditions. Catalytic testing revealed that Ru dispersion and oxidation state jointly determine activity and selectivity: extended metallic Ru or oxidized Ru nanoparticles favor complete hydrogenation to CH4, whereas isolated Ru species promote CO formation via the reverse water–gas shift pathway. The coexistence of these Ru configurations is associated with enhanced low temperature activity, while defect engineered supports improve stability against deactivation. Defect engineering of TiO2 provides an effective strategy to stabilize atomically dispersed Ru and to balance nanoparticles and atomic species, offering a versatile strategy to tune CO2 hydrogenation performance and advance the design of Ru based catalysts for sustainable hydrogenation processes.
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Nov 2026
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B23-Circular Dichroism
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Xi
Lei
,
Sibo
Peng
,
Nijas
Aliu
,
Rohanah
Hussain
,
Giuliano
Siligardi
,
Tiberiu-Marius
Gianga
,
Xin
Jin
,
Sabrina
Ruggiero
,
Shilpa
Chokshi
,
Luca
Urbani
,
Bernhard F.
Gibbs
,
Elena
Klenova
,
Gurprit S.
Lall
,
Gabriela
Dekany
,
Dietmar
Cholewa
,
Steffen M.
Berger
,
Maryam
Abooali
,
Inna M.
Yasinska
,
Song
Xu
,
Elizaveta
Fasler-Kan
,
Vadim V.
Sumbayev
Diamond Proposal Number(s):
[36941, 38189]
Abstract: Human cancer cells and malignant tumours operate immune evasion machinery, which consists of a set of cross-linked biochemical pathways that suppress the activities of immune cells, such as cytotoxic T cells and natural killer cells. Recent evidence demonstrated that the immune evasion machinery operated by human cancer cells is self-sustaining. However, the mechanisms underlying self-regulation of cancer immune evasion networks remain to be understood. Here we report for the very first time that the cell surface receptor CD44 acts as an enhancer of immune evasion activity in human cancer cells rather than an immune checkpoint per se. Furthermore, upon interaction with galectin-9, CD44 was found to alter cell membrane potential and induce the secretion of TGF-β. Secreted TGF-β displays autocrine and paracrine activities following TGF-β receptor (TGFBR) engagement, which was shown to then activate the Smad3 transcriptional pathway. CD44 complexed to galectin-9 allosterically enhances activity of the TGFBR complex and this was shown to substantially amplify the expression of immune checkpoint proteins crucially associated with suppressing the anti-cancer activities of cytotoxic lymphoid cells. We also demonstrated that this is a fundamental pathway used by human embryos to prevent immune rejection and by innate immune cells to facilitate anti-bacterial innate immune response. Cancer cells and malignant tumours hijack and successfully adapt this fundamental pathway to escape immune surveillance and suppress anti-cancer immune reactions. As such, this autocrine loop allows for the self-regulation of immune evasion networks operated by cancer cells and can be considered as a promising target for highly efficient immunotherapy of cancer.
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Nov 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[33047]
Open Access
Abstract: Human skeletal samples burned between 200 and 1000 °C, in both aerobic and anaerobic conditions, were probed by synchrotron-based Extended X-ray Absorption Fine Structure with a view to interpret heat-induced variations in chemical composition and structure. Heat-prompted changes in Ca2+ first and second coordination shells were unveiled (regarding PO43−, CO32− and/or OH− ligands). A higher crystallinity degree was found for 800-1000 °C burning temperatures as compared to 200-700 °C, in agreement with the higher amount of organic components in moderately heated samples. The unique local structural information delivered by XAS, particularly on the Ca2+ coordination environment which determines bone's structural features and degree of crystallinity, enabled an improved understanding of the heat-elicited changes undergone by bone, not previously accessed by other techniques. This is an innovative study, with a high impact in forensic and bioarchaeological research, focused on the analysis of burned human skeletal remains.
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Oct 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[39526]
Open Access
Abstract: There is increasing interest in using Fe-rich materials in cement, yet the Fe speciation in hydrated cement paste remains poorly understood. This study quantitatively investigates the fate of amorphous Fe in hydrated white Portland cement-fayalitic slag pastes with varying Fe contents cured for 3, 28, and 90 days. The results show that Fe precipitated as ferrihydrite and potentially adsorbed on calcium (alumino)silicate hydrate (C-(A)-S-H) after 3 days of hydration. Afterwards, Fe stabilised in Fe-siliceous hydrogarnet and Fe-adsorbed C-(A)-S-H phases, accounting for ∼15% and ∼ 85% of total reacted Fe, respectively, after hydration for 90 days. The high Fe uptake by C-(A)-S-H was mainly attributed to Fe(III) adsorption rather than Fe(II). Thermodynamic modelling combined with microstructural analysis supported the predominant distribution of Fe on the C-(A)-S-H phase. These findings can advance understanding in using reactive Fe-containing materials in Portland cement pastes and the development of their chemical and physical properties.
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Oct 2026
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B18-Core EXAFS
I20-Scanning-X-ray spectroscopy (XAS/XES)
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Diamond Proposal Number(s):
[33399, 38473, 34857]
Abstract: Divalent lanthanide ions can adopt complex 4fn5d1 electron configurations that formally violate the Aufbau principle. The blending of contracted 4f and diffuse 5d character strongly influences lanthanide frontier molecular orbitals, yet quantitative characterization of 5d electron participation in bonding remains challenging. To address this, we report L3-edge high-energy-resolution fluorescence-detected X-ray absorption near-edge structure (HERFD-XANES) and valence to core resonant inelastic X-ray scattering (V2C-RIXS) for a series of divalent lanthanide complexes [M(NHAriPr6)2] (M = Ce, Tb, Dy, and Yb; NHAr2iPr6 = N(H)C6H3-2,6-(C6H2-2,4,6-iPr3)2) and their trivalent precursors [M(NHAriPr6)2(I)], which all feature close metal–arene contacts. It is demonstrated that V2C-RIXS can be applied to quantify relative 5d covalency contributions to lanthanide–arene bonding. Analysis of divalent cerium, terbium, and dysprosium complexes reveals non-Aufbau (5d1) configurations, which show significant 5d–arene δ-bond covalency and stabilization of the associated bonding orbitals. V2C-RIXS spectra are accurately simulated and compared with UV–vis–NIR results using density functional theory (DFT)/restricted open configuration interaction with singles (ROCIS) calculations. A detailed assignment of spectral features and correlation to predicted electron configurations defines a trend of increased 5d covalency for these complexes relative to their trivalent precursors. Conversely, the divalent ytterbium complex has an Aufbau configuration, 4f14, and shows markedly reduced 5d covalency relative to its trivalent precursor.
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Oct 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[37736]
Open Access
Abstract: Calcium aluminosilicate (CAS) glass was assessed for its ability to immobilize elements present in Plutonium-Contaminated Materials (PCM) including metals (Fe and Cr), polyvinyl chloride (PVC), and Pu (investigated using the nonradioactive surrogates Ce and Hf). Industrial-scale trial melts containing simulant inorganic and organic PCM were characterized to ascertain glass homogeneity, structure, and chemical durability. They were highly durable, comprising a glassy matrix with anorthite (CaAl2Si2O8) crystals. Redox conditions were such that 5–7 mol % Fe, from the melted steel drums, was incorporated in the glass phase, predominantly as Fe2+ in place of Ca, with no significant change to the glass structure. The solubility of Ce and Hf (as Pu surrogates), mixed metal, and PVC in CAS glass was investigated using a series of laboratory-scale melts and shown to exceed those measured in borosilicate glasses. Ce was incorporated in a mixed Ce3+/4+ valence state up to waste loadings of > 3.66 mol % CeO2, while Hf4+ was incorporated to the same extent with no significant change to the CAS structure. Fe was fully incorporated up to 3.43 mol %, but the solubility limit for Cr2O3 was reached between 0.5 and 1 mol %. Laboratory glasses were melted in air, so the majority of Fe was incorporated as Fe3+ in tetrahedral coordination, leading to structural differences between laboratory- and industrial-scale CAS. Chlorine incorporation was low in all systems, likely due to volatilization rather than approaching the solubility limit of Cl in CAS glass.
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Oct 2026
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I05-ARPES
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Cedric
Schmitt
,
Lukas
Gehrig
,
Kilian
Strauß
,
Jonas
Erhardt
,
Merit
Spring
,
Bing
Liu
,
Matthew D.
Watson
,
Han
Gao
,
Hanbo
Xiao
,
Zhongkai
Liu
,
Gang
Li
,
Giorgio
Sangiovanni
,
Jörg
Schäfer
,
Ralph
Claessen
,
Simon
Moser
Diamond Proposal Number(s):
[41909]
Abstract: Circular dichroism in angle-resolved photoemission spectroscopy (CD-ARPES) is widely used to probe orbital angular momentum (OAM) and Berry-curvature-related phenomena in two-dimensional quantum materials. However, in many materials, conventional micron-scale measurements often average over domains with opposite OAM polarization, canceling intrinsic dichroic signals and leaving spectra dominated by extrinsic asymmetries arising from photoelectron final-state interference. Here, we combine circularly polarized light with NanoARPES to achieve spatially resolved CD-ARPES with sub-800 nm resolution. By isolating individual domains, this approach enables direct access to the intrinsic OAM texture. As a model system, we investigate the K/K′ point valley states of the quantum spin Hall insulator indenene─a triangular indium monolayer epitaxially grown on SiC(0001)─where substrate-induced terraces host alternating valley configurations whose dichroic response is averaged out in conventional measurements. Terrace-resolved NanoARPES disentangles these contributions, allowing direct visualization of oppositely polarized domains and revealing the OAM texture associated with a topological band inversion. Our results establish spatially resolved CD-ARPES as a robust approach for isolating intrinsic OAM contrast by eliminating domain averaging and correcting for extrinsic geometry-dependent contributions. This enables direct access to the Berry curvature near the Fermi level, providing a powerful probe of the system’s intrinsic topological character.
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Oct 2026
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Jinhwan
Byeon
,
Nick
Gys
,
Jorid
Smets
,
Ali
Azimi
,
Lukas
Nulens
,
João
Fernandes
,
Leen
Boullart
,
Dowon
Kim
,
Kevin M.
Dorney
,
Jesus
Gandara-Loe
,
Juhyung
Park
,
Min Jong
Jeong
,
Sangjin
Kim
,
Sukwon
Hong
,
Tomasz
Sobol
,
Barbara
Wolanin
,
Tom
Hauffman
,
Joris Van De
Vondel
,
Rob
Ameloot
Diamond Proposal Number(s):
[41436]
Abstract: Dry-deposited metal–organic resists are key enablers for advanced patterning processes in next-generation semiconductor manufacturing. Here, we report halogenated amorphous zeolitic imidazolate framework (a-ZIF) resists deposited entirely by a dry process, which exhibit a pronounced irradiation-source-dependent tone conversion. Smooth a-ZIF films were grown by chemical vapor deposition (CVD) using 4,5-diiodoimidazole (DI-Im) precursors. Partial in situ thermal decomposition of DI-Im produces a ternary linker mixture (DI-Im, 4-iodoimidazole, imidazole), promoting the growth of uniform, amorphous films. Under electron-beam (e-beam) exposure, the resist operates in a positive-tone mode with high sensitivity (D50 = 0.15 mC cm–2, comparable to commercial PMMA resists) and resolves 100 nm line-and-space and 80 nm contact-hole patterns. In contrast, EUV exposure yields high sensitivity in negative-tone development (D50 = 65 mJ cm–2) and exhibits a nonmonotonic dose–thickness response in positive-tone development. We demonstrate positive-tone EUV patterning of 90 nm line-and-space features. X-ray photoelectron and near-edge X-ray absorption fine structure spectroscopy trace the tone conversion to distinct reaction pathways: high-energy primary electrons under e-beam exposure drive imidazole ring decomposition into soluble polar fragments, giving rise to the positive-tone response, whereas the low-energy electrons generated under EUV cleave C–I bonds while retaining the ring, and the resulting poorly soluble recombination products account for both the negative-tone behavior and the nonmonotonic positive-tone response. Identifying the electron-energy regimes and reaction pathways responsible for each behavior provides a basis for engineering the resist response through linker design. These results illustrate that electron-beam exposure cannot serve as a universal chemical proxy for EUV lithography.
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Oct 2026
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B18-Core EXAFS
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Abstract: Dual-atom catalysts (DACs) surpass the limitations of single-atom catalysts by harnessing synergy between adjacent metal sites. Herein, we propose a novel strategy employing d-p orbital synergistic modulation in Fe-Sb DACs. Combined density functional theory and molecular dynamics simulations reveal that the significant d-p orbital synergistic regulation between Fe and Sb sites promotes O2 adsorption and activation, lowers the energy barrier for Osingle bondO bond cleavage, and optimizes water desorption. As a proof-of-concept, Fe/Sb DACs anchored on a nitrogen-doped carbon matrix (Fe/Sb-N-C) were synthesized. The atomic-level local coordination of Fe-Sb dual atoms was systematically characterized by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption fine structure (XAFS) analyses. The as-fabricated Fe/Sb-N-C exhibits exceptional alkaline oxygen reduction reaction (ORR) performance, featuring a half-wave potential of 0.92 V and outstanding durability. Aqueous Zn-air batteries equipped with Fe/Sb-N-C achieve a high maximum power density of 196 mW cm-2 and a specific capacity of 795 mAh g-1. Furthermore, quasi-solid-state Zn-air batteries demonstrate wide-temperature operability (-30 to 60 °C) and stability under high current densities. This work establishes d-p orbital synergy as a new paradigm for designing high-efficiency ORR catalysts, broadening their application in energy devices across extreme temperatures.
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Sep 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[40080]
Open Access
Abstract: Metal–organic frameworks (MOFs) offer tunable platforms for water purification, yet the disposal of contaminant-loaded frameworks creates secondary waste and limits their sustainable use. Here, a circular adsorbent-to-catalyst strategy is demonstrated using a freeze-dried two-dimensional Cu–imidazolate framework (FD-BNMG-1). Prepared through scalable aqueous synthesis and lyophilization, FD-BNMG-1 removes more than 95% of Mn(II) from water within 24 h and reaches a maximum adsorption capacity of 370 mg g−1, the highest reported for an unmodified MOF adsorbent toward Mn(II). Cu and Mn K-edge X-ray absorption spectroscopy, supported by powder X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy with energy-dispersive X-ray spectroscopy, and nitrogen sorption analysis, reveals that Mn sequestration drives substantial structural and electronic reconstruction. The Cu coordination number increases from 4.0 to 5.7, long-range Cu order is disrupted, and an open, redox-heterogeneous Mn-integrated Cu coordination nanonetwork is formed. Rather than being discarded, the resulting spent material, Mn@FDB, is directly repurposed as a heterogeneous catalyst for oxidative C–O cross-coupling reactions, affording aryl ester products in yields up to 84% and retaining activity over multiple cycles. This transformation demonstrates how adsorption can program a functional second life for contaminant-loaded MOFs. The approach integrates pollutant capture, material transformation, and efficient catalytic valorization.
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Sep 2026
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