B18-Core EXAFS
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Diamond Proposal Number(s):
[34632]
Abstract: Polychlorinated aromatic hydrocarbons (PCAHs) in flue gas seriously threaten the environment and human health, and Ru-based catalysts exhibit efficient oxidation property for PCAHs removal. However, the current Ru catalysts either have high Ru loading/non-stable structure or are developed empirically whilst lack of design mechanism. Herein, a robust Ru single atom catalyst (0.5 Ru1/TiO2) was designed based on metal-support interaction for o-DCB (o-dichlorobenzene, a typical PCAHs) degradation, and it revealed significantly better oxidation activity with T50 = 207.4 °C and T90 = 243.5 °C than its contrast with weak metal-support interaction (0.5 RuNP/TiO2, T50 = 247.4 °C, T90 > 300 °C). In addition, 0.5 Ru1/TiO2 exhibited much better chlorine resistance stability, maintaining >90% o-DCB conversion for 700 min versus∼70% on 0.5 RuNP/TiO2. The superior performance of 0.5 Ru1/TiO2 was attributed to its stronger metal-support interaction between Ru and TiO2, verified by H2-TPR, which offered higher active oxygen species (22.4%), more Lewis acid (0.675 mmol/g) and higher exposed Ru ratio (> 90.0%) than 0.5 RuNP/TiO2 (15.0%, 0.068 mmol/g, 28.6%, respectively). The above properties can not only enhance o-DCB adsorption/activation and weaken its Csingle bondCl bonds but also favor partial/deep oxidation and remove deposited chlorine on 0.5 Ru1/TiO2, proved by in situ FT-IR. Moreover, notable higher water resistance under different water vapor and applicability under varied pollutant concentration were observed on the robust Ru1/TiO2. This work reveals insightful function-property study on Ru single atom catalysts for PCAHs oxidative removal.
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May 2026
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I06-Nanoscience (XPEEM)
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Diamond Proposal Number(s):
[31889]
Abstract: Rare-earth iron garnet (RE3Fe5O12) films are promising insulating ferrimagnets. They can show low magnetic damping, perpendicular magnetic anisotropy, and ultrafast spin dynamics, which makes them ideal for spin transport applications. In this work, we investigate the interaction between the magnetic sublattices in Er3Fe5O12 thin films grown by pulsed laser deposition on a Gd3Ga5O12 substrate. Structural and magnetic characterization reveals high-quality single-crystal growth, with a compensation temperature close to the reported bulk value (∼80 K). Magnetic phase diagrams based on element-specific measurements map out the regions where ferrimagnetic, canted, and aligned phases are stable across the compensation temperature. The micromagnetic dynamics resulting from perpendicular magnetic pulse perturbation of an in-plane magnetized layer was investigated at room temperature and revealed complex configurations. These results are key features for modulating magnetization dynamics through the compensation phenomenon, which is essential for spin-based devices operating in a low-temperature regime.
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Mar 2026
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Shan
Dai
,
Xiangdi
Zeng
,
Benjamin J.
Moore
,
Yuxiang
Zhu
,
Yuhang
Yang
,
Zi
Wang
,
Luyan
Li
,
Te
Wang
,
Ivan
Da Silva
,
Luke
Keenan
,
Floriana
Tuna
,
Daniel
Lee
,
Sarah
Day
,
Lucy
Saunders
,
Martin
Schroeder
,
Sihai
Yang
Abstract: Metal–organic framework (MOF) materials share some common features with metalloenzymes including site-isolated metal centers that template dynamic substrate activation within a functionalized cavity or pocket. We report the light-induced reversible binding of CO2 in a cerium-based MOF, Ce-UiO-66-NH2, incorporating an amino functionalized linker, which enables photoreduction of CO2 to CO in H2O without using sacrificial agents. A production rate for CO of 126 μmol·g–1·h–1 with 100% selectivity is observed, outperforming its non-amine analogue (Ce-UiO-66) and benchmark catalysts reported to date. In situ infrared, X-ray absorption, electron paramagnetic resonance and transient absorption spectroscopy reveal that photoexcitation induces a ligand-to-metal charge transfer to generate transient open Ce(III) sites that bind CO2 in a μ-(η1-O)(η1-C) binding mode. This binding is reversible and activates CO2 for subsequent photoreduction to CO. This work will promote the design of photocatalysts capable of synthesizing fuels from CO2.
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Mar 2026
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[40142]
Open Access
Abstract: Triboelectric nanogenerators (TENGs), which convert mechanical energy into electrical signals, have emerged as apromising platform for self-powered motion sensing. However, the development of high-sensitivity TENG sensors remains limited by the availability of tunable and efficient tribo-positive materials, which are electron donors. In this work, we present a material design strategy based on the incorporation of electron-donating functionalized metal–organic framework (MOF) fillers into a polyurethane (PU) polymer matrix. Three functional groups (−CH3, −NH2, and −OH) were systematically studied to investigate their influence on triboelectric performance. The resulting composite membranes demonstrated tunable charge-donating behavior and improved electrical output, with the −OH-modified MOF yielding the highest electrical output of 197.6 ± 1.3 V and 0.47 ± 0.08 μA/cm2, which are 2.3 and 3.2 times higher than that of the pristine PU. The enhanced charge-donating mechanism was elucidated through a combination of advanced micro- and nanoscale chemical and mechanical analysis. Theoretical calculations employing ab initio density functional theory (DFT) were performed to reveal the electron distribution within the periodic MOF structure. Furthermore, the practical application of the optimized TENG device was demonstrated in a single-electrode shear sensor configuration, exhibiting high sensitivity in sliding motion detection. This study highlights a scalable and biocompatible strategy for improving tribo-positive materials and advancing the performance of tunable TENG-based sensors to enable shear force monitoring.
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Mar 2026
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I09-Surface and Interface Structural Analysis
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O.
Tkach
,
S.
Fragkos
,
Deepnarayan
Biswas
,
J.
Liu
,
O.
Fedchenko
,
Y.
Lytvynenko
,
S.
Babenkov
,
D.
Zimmer
,
Q. L.
Nguyen
,
S.
Chernov
,
D.
Kutnyakhov
,
M.
Scholz
,
N.
Wind
,
A.
Gloskovskii
,
F.
Pressacco
,
J.
Dilling
,
L.
Bruckmeier
,
M.
Heber
,
L.
Wenthaus
,
G.
Brenner
,
D.
Puntel
,
P. E.
Majchrzak
,
D.
Liu
,
F.
Scholz
,
J. A.
Sobota
,
J. D.
Koralek
,
G.
Dakovski
,
A.
Mehta
,
N.
Sirica
,
M.
Hoesch
,
C.
Schlueter
,
L. V.
Odnodvorets
,
Y.
Mairesse
,
T.-L.
Lee
,
A.
Kunin
,
K.
Rossnagel
,
Z. X.
Shen
,
H. J.
Elmers
,
S.
Beaulieu
,
G.
Schönhense
Abstract: A new type of objective lens has recently been proposed for use in x-ray photoemission electron microscopes (XPEEMs) and momentum microscopes. Adding a ring electrode concentric with the extractor allows the field in the gap between the sample and the extractor to be shaped. Forming a lens field in this gap reduces the field strength at the sample by up to an order of magnitude. This mitigates the risk of field emission, particularly for cleaved samples with sharp edges. A retarding field can redirect all slow electrons, thus eliminating the primary contribution to the space-charge interaction. Here, we present the first experimental investigation of the new lens, examining its performance at photon energies ranging from the extreme ultraviolet (XUV) produced by a high-harmonic generation-based source to soft and hard x rays at two synchrotron facilities. The gap lens in a region without electrodes enables large working distances up to 23 mm. Reduced aberrations allow for larger fields of view in both k-space and real-space imaging, with resolutions comparable to those of conventional cathode lenses. However, field strengths are an order of magnitude smaller. The zero-field mode enables the study of 3D structured objects and is, therefore, beneficial for small cleaved samples as well as for operando devices involving top electrodes. The repeller mode reduces space-charge effects but results in a smaller k-field diameter. This reduction ranges from 10% at hard x-ray energies to 50% in the XUV range. The usable energy interval is also reduced by a factor of two. In time-of-flight XPEEM mode, the raw data show a resolution of 250 nm, which can be improved to better than 100 nm through data processing.
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Mar 2026
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I18-Microfocus Spectroscopy
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Diamond Proposal Number(s):
[35970]
Open Access
Abstract: We have determined the pressure dependence of the ratio S6+/(S2-+S6+) in silicate melts by measuring the effects of pressure on the concentrations of sulfide (S2-) and sulfate (SO42-) species at known fugacities of sulfur and oxygen. For S2- we controlled f(S2) using mixtures of Ag and Ag2S with oxygen fugacity held at the CCO buffer. For S6+ we measured molten CaSO4 solubility as a function of pressure. We define sulfide capacity and sulfate capacity from the S2- and S6+ contents of the melt as (Fincham and Richardson, 1954): and .
The dependences of and on pressure were found, with P in bars and T in K, to be:
and . The negative pressure dependences are due to the differences in partial molar volumes between sulfide S2- and oxide O2– species and sulfate SO42 -and oxide O2– which we calculate to be ∼ 10.7 cm3/mol and ∼ 31.6 cm3/mol respectively. These are similar to the differences in volumes between CaS and CaO (10.96 cm3/mol) and CaSO4 and CaO (29.2 cm3/mol).
We used these and equations to calculate the pressure dependence of the “crossover” oxygen fugacity at which S2- transforms to S6+ in silicate melts of different composition. The crossover is shifted in absolute f(O2) by + 0.25 log units or, relative to FMQ, by −0.41 log units as pressure is increased from 1 bar to 1 GPa at 1400 °C. This demonstrates that the effect of pressure on sulfur oxidation state is small and may be neglected for many purposes. The pressure dependence of the S2-—S6+ crossover means that there would be some electron exchange between Fe2+ and S6+ during decompression in a closed system (S2-+8Fe3+ = S6++8Fe2+). The effect is small, but largest in melts which start at oxygen fugacities close to and above FMQ and would, for a basalt containing 1500 ppm S lead to an increase in oxygen fugacity of 0.4 to 0.5 logf(O2) units during decompression from 1.5 GPa to 1 bar.
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Mar 2026
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I14-Hard X-ray Nanoprobe
I20-Scanning-X-ray spectroscopy (XAS/XES)
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Diamond Proposal Number(s):
[34837, 38234, 38452]
Open Access
Abstract: Metals play an essential role in cellular homeostasis and are key components of several formulations currently used in the clinic. Synchrotron-based X-ray microscopy at submicron resolution is a powerful approach to map intracellular elemental distributions and to monitor how these patterns change upon genetic or pharmacological perturbations. However, existing sample-preparation protocols often rely on costly and highly specialized equipment for vitrification and dehydration, limiting their widespread adoption. Here, we present an adapted plunge-freezing and freeze-drying workflow that enables the preparation of mammalian cell samples for X-ray fluorescence (XRF) and X-ray absorption spectroscopy (XAS) studies with submicron resolution in a cost-effective and versatile manner. Furthermore, we define acquisition parameters optimized for the reliable detection of low-abundance metals, such as endogenous iron. We anticipate that this accessible protocol will facilitate the broader implementation of synchrotron-based inner-shell spectromicroscopy in cell biology.
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Mar 2026
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B18-Core EXAFS
I15-1-X-ray Pair Distribution Function (XPDF)
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Shanshan
Xu
,
Matthew E.
Potter
,
Raquel
Simancas
,
Lucy
Costley-Wood
,
Boya
Qiu
,
Xuzhao
Liu
,
Cristina
Stere
,
M. Asuncion
Molina
,
Danial
Farooq
,
Floriana
Tuna
,
Dingyue
Zhang
,
Shuanglin
Zhang
,
Huanhao
Chen
,
Shengzhe
Ding
,
Xinrui
Wang
,
Sarayute
Chansai
,
Matthew
Lindley
,
Sarah J.
Haigh
,
Armando
Ibraliu
,
Lan
Lan
,
Piu
Chawdhury
,
Mariyam
Bi
,
Otis
Leahair
,
Yilai
Jiao
,
Min
Hu
,
Qiang
Liu
,
Toru
Wakihara
,
Xiaolei
Fan
,
Andrew M.
Beale
,
Christopher
Hardacre
Diamond Proposal Number(s):
[33381, 32971, 36241]
Open Access
Abstract: Methanol synthesis via non-thermal plasma (NTP) catalytic CO2 hydrogenation provides a sustainable approach to chemical and fuel production with potential in carbon emissions reduction. However, the underlying mechanisms remain unclear. Here we evaluate the mechanism of NTP-catalytic CO2 hydrogenation over Cu–Zn/ZSM-5 through operando X-ray absorption spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy and in situ X-ray pair distribution function. We found that Zn enhances Cu dispersion and reducibility, as well as forming active Cu/ZnO interfacial sites. Beyond the conventional formate pathway on metallic Cu, these interfaces enable an additional CO hydrogenation route, enhancing methanol yield. NTP also promotes gas-phase CO2 dissociation to CO, bypassing the reverse water–gas shift step required in thermal catalysis. No Cu/Zn alloy formation was observed, underscoring the importance of metallic Cu and Cu/ZnO interfaces under NTP conditions. Furthermore, NTP stabilizes reduced Cu species, preventing re-oxidation and ensuring sustained catalytic activity. These findings advance the mechanistic understanding of NTP-assisted catalysis.
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Feb 2026
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B18-Core EXAFS
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Yuan
Liao
,
Yang
Fu
,
Fengzhan
Sun
,
Yuanshen
Wang
,
David C.
Lloyd
,
Zhiyong
Zhao
,
Zipei
Wan
,
Federico
Grillo
,
Arvydas
Ruseckas
,
Edward
Ogugu
,
John T. S.
Irvine
Open Access
Abstract: As the global energy landscape shifts to a green hydrogen economy, efficient and stable visible-light photocatalysts are increasingly central to optimizing solar-to-hydrogen conversion. Here, a Sr-site-deficient perovskite photocatalyst (R-Pt/Sr0.95Ti0.9Cr0.1O3-δ) was synthesised by a solid-state method, followed by Pt impregnation and hydrogen reduction post treatment. The introduction of A-site deficiency effectively tunes the band structure and facilitates hydrogen evolution, doubling activity compared to stoichiometric analogs. Besides, A-site deficiency reduces overall cation charge and promotes Cr4+ formation. Through spectroscopy and thermal analysis, Cr4+ was identified in the Sr0.95Ti0.9Cr0.1O3-δ perovskite, revealing unexplored oxidation state dynamics. Upon reduction, Cr4+ converts to Cr3+, creating oxygen vacancies and eliminating hole-trap sites. The resulting synergistic active sites greatly boost photocatalytic hydrogen evolution. Specifically, the R-Pt/Sr0.95Ti0.9Cr0.1O3-δ achieved 120.46 μmol/gcat/h under full spectrum and 68.66 μmol/gcat/h under visible light (λ ≥ 420 nm), representing twice and 5 times enhancements relative to stoichiometric R-Pt/SrTi0.9Cr0.1O3-δ and unreduced Pt/Sr0.95Ti0.9Cr0.1O3-δ in visible light separately. This work demonstrates that combining A-site engineering and valence-state modulation provide a helpful strategy for designing high-performance visible-light photocatalysts.
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Feb 2026
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B18-Core EXAFS
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Yingxiang
Zhao
,
Yingjie
Zhao
,
Xinyue
Zhou
,
Haiwei
Guo
,
Qiqi
Yin
,
Yutao
Jiang
,
Haiyan
He
,
Na
Liu
,
Gengbo
Ren
,
Christopher M. A.
Parlett
,
Changzhi
Li
Diamond Proposal Number(s):
[34632]
Abstract: M–N–C single-atom catalysts (SACs) represent promising candidates owing to their atomically dispersed active sites and tunable catalytic properties and have shown broad potential in various catalysis reactions. However, the mechanisms and true active sites involved in lignin conversion, particularly oxidative depolymerization, remain unclear. Herein, a Ru–N–C SAC with a well-defined configuration, including coordination environment and coordination number, was synthesized via a straightforward ball-milling method for lignin oxidation. The Ru–N–C SAC prepared with 12 h of ball milling demonstrated high catalytic performance in the oxidative depolymerization of various β-O-4 model compounds and diverse lignin feedstocks. Structural analysis via X-ray absorption spectroscopy demonstrated that the Ru–N4 motif constitutes the predominant coordination environment in Ru–N–C, which is regarded as the primary active site in activating O2 into superoxide radicals, as confirmed by free-radical quenching experiments and electron paramagnetic resonance analysis; meanwhile, it also served as a basic site in polarizing Cβ–H bonds in β-O-4 that favored C–O/C–C bond cleavage, which was disclosed by CO2 temperature-programmed desorption and electron localization function analysis. The critical role of Ru–N4 in the activation of O2 and C–O/C–C bond cleavage was further confirmed by density functional theory calculation, which indicated that the Ru–N4 center exhibits strong adsorption toward both the O2 and β-O-4 linkages. This work provides a deep understanding on the active sites within Ru–N–C SACs for lignin oxidative cleavage and offers great potential on the rational design of next-generation SACs in biomass valorization.
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Feb 2026
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