B18-Core EXAFS
B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
|
Boya
Tang
,
David
Brooks
,
Meng
He
,
Yinlin
Chen
,
Zhaozhao
Hu
,
Xue
Han
,
Jiangnan
Li
,
Siyu
Zhao
,
Jiarui
Fan
,
Yukun
Ye
,
Ivan
Da Silva
,
Cheng
Li
,
Zi
Wang
,
Lutong
Shan
,
Bing
Han
,
Weiyao
Li
,
Daniil
Polyukhov
,
Bing
An
,
Catherine
Dejoie
,
Martin
Wilding
,
Shaojun
Xu
,
Meredydd
Kippax-Jones
,
Zhaodong
Zhu
,
Yujie
Ma
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Mark D.
Frogley
,
Louise S.
Natrajan
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[37900, 37887, 36450]
Abstract: Photocatalytic synthesis of hydrogen peroxide (H2O2) from oxygen (O2) is a challenging process. Metal–organic framework (MOF) materials are emerging photocatalysts with potential tunable light absorption properties. Herein, we report a rhenium (Re) modified Zr-based MOF, Re10-MFM-67, in which active Re sites are incorporated into MFM-67 by partial replacement of 9,9′-bianthracene-10,10′-dicarboxylic acid (H2L1) with a [(H2L2)ReI(CO)3Cl] (H2L2 = 2,2′-bipyridine-5,5′-dicarboxylic acid) moiety. Re10-MFM-67 (10 refers to the molar percentage content of Re complex within the material) exhibits broadband light absorption with an exceptional rate of formation of H2O2 from O2 of 8.50 mmol gcat–1 h–1 and a record turnover frequency (TOF) of 28.7 h–1 under visible light irradiation (λ > 400 nm). Synchrotron powder X-ray diffraction (SPXRD) and neutron powder diffraction (NPD) confirm the structure of Re10-MFM-67, and together with extended X-ray absorption fine structure (EXAFS) analysis establish the coordination environment and binding of the [ReI(CO)3Cl] moiety within the framework structure. In situ electron paramagnetic resonance (EPR) spectroscopy suggests that photocatalytic H2O2 generation on Re10-MFM-67 occurs via a two-step oxygen reduction reaction (ORR) pathway with the superoxide anion formed as an intermediate. This study promotes the design of MOF-based photocatalysts with conjugated ligands for efficient photosynthesis.
|
Jul 2025
|
|
|
|
Open Access
Abstract: Publishing supporting data significantly impacts researchers' productivity, especially in experiments requiring extensive tracking of data, processing steps, parameters, and outputs. A managed workflow environment, combined with RO-Crates, addresses these data management challenges. Workflows provide an alternative for handling complex data analyses by orchestrating various processing tools. The RO-Crate format, a community-driven proposal for packaging data, provenance, and workflows, facilitates publishing and reproducibility. The Galaxy workflow management system integrates workflows and RO-Crates, enabling the export of analyses, which can be shared and restored by other users. Using Galaxy, we demonstrate how to improve support for reproducibility. We tested our approach by designing an experiment using diverse supporting data from selected papers. In the experiment, we identified specific FAIRness and completeness issues hindering result reproduction, even when authors made significant efforts to document and publish their supporting data. In comparison, the proposed approach supports reproducibility by packaging datasets in RO-Crate format, streamlining the process. The Galaxy RO-Crates, published as supporting materials, enhance data sharing, transparency, and reproducibility, thus supporting the advancement of FAIR research practices in catalysis research.
|
Mar 2025
|
|
B18-Core EXAFS
|
Nivetha
Jeyachandran
,
Wangchao
Yuan
,
Xiang
Li
,
Akshayini
Muthuperiyanayagam
,
Stefania
Gardoni
,
Jiye
Feng
,
Qingsheng
Gao
,
Martin
Wilding
,
Peter
Wells
,
Devis
Di Tommaso
,
Cristina
Giordano
Diamond Proposal Number(s):
[29721]
Open Access
Abstract: The rising levels of CO2 have spurred growing concerns for our environment, and curbing CO2 emissions may not be practically viable with the expanding human population. One attractive strategy is the electrochemical CO2 reduction (CO2RR) into value added chemicals but because of the chemical inertness of the CO2 molecule, the electrochemical reduction requires a suitable catalyst. Cu-based catalysts have been largely investigated for CO2RR, however, the difficulty achieving a high selectivity and faradaic efficiency towards specific products, especially hydrocarbons, is still a challenge, alongside the concern over cost, stability and scarcity of the metal catalyst. The present research focuses on tuning the crystallinity of Cu nanoparticles via a green, cost-friendly, and facile method, called the urea glass route. Remarkably, the incorporation of a selected nitrogen-carbon rich source (namely, 4,5 dicyanoimidazole) at low temperatures allow the formation of an oxidized derived amorphous Cu system, whilst a second thermal treatment enables the transformation to crystalline Cu0. We found that the combination of surface Cu0 and Cu1+ (observed via XPS studies) present in our amorphous and crystalline Cu nanoparticles leads to interesting differences in the final catalytic activity when tested under CO2 reaction conditions. The combination of extended X-ray absorption fine structure (EXAFS) experiments and molecular dynamics simulations provides compelling evidence for the amorphous and metallic nature of Cu nanoparticles.
|
Dec 2024
|
|
B18-Core EXAFS
|
Santhosh K.
Matam
,
Preetam K.
Sharma
,
Eileen H.
Yu
,
Charalampos
Drivas
,
Mohammad D.
Khan
,
Martin
Wilding
,
Nitya
Ramanan
,
Diego
Gianolio
,
Mark A.
Isaacs
,
Shaoliang
Guan
,
Philip R.
Davies
,
C. Richard A.
Catlow
Diamond Proposal Number(s):
[29271]
Open Access
Abstract: We present a novel operando X-ray absorption spectroscopic (XAS) flow cell, consisting of a gas chamber for CO2 and a liquid chamber for the electrolyte, to monitor electrochemical CO2 reduction (eCO2R) over a gas diffusion electrode (GDE). The feasibility of the flow cell is demonstrated by collecting XAS data (during eCO2R over Cu-GDE) in a transmission mode at the Cu K-edge. The dynamic behaviour of copper during eCO2R is captured by XAS which is complemented by quasi in situ Raman and X-ray photoelectron spectroscopy (XPS). The linear combination analyses (LCA) of X-ray absorption near edge structure (XANES) indicate that copper oxides are the only species present during the first 20 min of eCO2R, corroborated by complementary Raman and XPS. Significantly, the complementary spectroscopic data suggests that the copper composition in the bulk and on the surface Cu-GDE evolve differently at and above 30 min of eCO2R. LCA indicates that at 60 min, 77% of copper occurs as metallic Cu and the remainder 23% in Cu (II) oxidation state, which is not evident from XPS that shows 100% of copper in < 2+ oxidation state. Thus, the Cu (II) is probably in the bulk of Cu-GDE, as also evident from Raman. The ethylene formation correlates very well with the occurrence of copper oxides and hydroxide species in Cu-GDE. The results not only demonstrate the applicability and versatility of the operando XAS GDE flow cell, but also illustrate the unique advantages of combining XAS with complementary Raman and XPS that enables the monitoring of the catalyst structural evolution from the bulk to surface and surface adsorbed species.
|
Dec 2024
|
|
B18-Core EXAFS
I11-High Resolution Powder Diffraction
|
Lutong
Shan
,
Yujie
Ma
,
Shaojun
Xu
,
Meng
Zhou
,
Meng
He
,
Alena M.
Sheveleva
,
Rongsheng
Cai
,
Daniel
Lee
,
Yongqiang
Chen
,
Boya
Tang
,
Bing
Han
,
Yinlin
Chen
,
Lan
An
,
Tianze
Zhou
,
Martin
Wilding
,
Alexander S.
Eggeman
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Sarah J.
Haigh
,
Xinchen
Kang
,
Buxing
Han
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[33115, 31729]
Open Access
Abstract: The design and preparation of efficient catalysts for ammonia production under mild conditions is a desirable but highly challenging target. Here, we report a series of single-atom catalysts [M-SACs, M = Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Mo(II)] derived from UiO-66 containing structural defects and their application to electrochemical reduction of nitrate (NO3-) to ammonia (NH3). Cu-SAC and Fe-SAC exhibit remarkable yield rates for NH3 production of 30.0 and 29.0 mg h−1 cm−2, respectively, with a high Faradaic efficiency (FENH3) of over 96% at −1.0 V versus the reversible hydrogen electrode. Importantly, their catalytic performance can be retained in various simulated wastewaters. Complementary experiments confirmed the nature of single-atom sites within these catalysts and the binding domains of NO3- in UiO-66-Cu. In situ spectroscopic techniques, coupled with density functional theory calculations confirm the strong binding of NO3- and the formation of reaction intermediates, thus facilitating the catalytic conversion to NH3.
|
Jun 2024
|
|
B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
B18-Core EXAFS
E02-JEM ARM 300CF
|
Longxiang
Liu
,
Liqun
Kang
,
Jianrui
Feng
,
David G.
Hopkinson
,
Christopher S.
Allen
,
Yeshu
Tan
,
Hao
Gu
,
Iuliia
Mikulska
,
Veronica
Celorrio
,
Diego
Gianolio
,
Tianlei
Wang
,
Liquan
Zhang
,
Kaiqi
Li
,
Jichao
Zhang
,
Jiexin
Zhu
,
Georg
Held
,
Pilar
Ferrer
,
David
Grinter
,
June
Callison
,
Martin
Wilding
,
Sining
Chen
,
Ivan
Parkin
,
Guanjie
He
Diamond Proposal Number(s):
[30614, 32058, 32035, 32117, 33466, 29271]
Open Access
Abstract: Electrochemical hydrogen peroxide (H2O2) production (EHPP) via a two-electron oxygen reduction reaction (2e- ORR) provides a 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 the correlation between structural configurations and performances in neutral media, remains underexplored. Herein, a series of ultralow metal-loading M-N-C electrocatalysts are synthesized and investigated for the EHPP process in the neutral electrolyte. CoNCB material with the asymmetric Co-C/N/O configuration exhibits the highest EHPP activity and selectivity among various as-prepared M-N-C electrocatalyst, with an outstanding mass activity (6.1 × 105 A gCo−1 at 0.5 V vs. RHE), and a high practical H2O2 production rate (4.72 mol gcatalyst−1 h−1 cm−2). Compared with the popularly recognized square-planar symmetric Co-N4 configuration, the superiority of asymmetric Co-C/N/O configurations is elucidated by X-ray absorption fine structure spectroscopy analysis and computational studies.
|
May 2024
|
|
E01-JEM ARM 200CF
E02-JEM ARM 300CF
|
Diamond Proposal Number(s):
[31082]
Open Access
Abstract: Despite extensive efforts to develop high-performance H2 evolution catalysts, this remains a major challenge. Here, we demonstrate the use of Cd/Pt precursor solutions for significant photocatalytic H2 production (154.7 mmol g-1 h-1), removing the need for a pre-synthesized photocatalyst. In addition, we also report simultaneous in-situ synthesis of Pt single-atoms anchored CdS nanoparticles (PtSA-CdSIS) during photoirradiation. The highly dispersed in-situ incorporation of extensive Pt single atoms on CdSIS enables the enhancement of active sites and suppresses charge recombination, which results in exceptionally high solar-to-hydrogen conversion efficiency of ~1% and an apparent quantum yield of over 91% (365 nm) for H2 production. Our work not only provides a promising strategy for maximising H2 production efficiency but also provides a green process for H2 production and the synthesis of highly photoactive PtSA-CdSIS nanoparticles.
|
Feb 2023
|
|
I22-Small angle scattering & Diffraction
|
Mario
Gonzalez-Jimenez
,
Trent
Barnard
,
Ben A.
Russell
,
Nikita V.
Tukachev
,
Uroš
Javornik
,
Laure-Anne
Hayes
,
Andrew J.
Farrell
,
Sarah
Guinane
,
Hans M.
Senn
,
Andrew J.
Smith
,
Martin
Wilding
,
Gregor
Mali
,
Motohiro
Nakano
,
Yuji
Miyazaki
,
Paul
Mcmillan
,
Gabriele C.
Sosso
,
Klaas
Wynne
Diamond Proposal Number(s):
[28529]
Open Access
Abstract: A common feature of glasses is the “boson peak”, observed as an excess in the heat capacity over the crystal or as an additional peak in the terahertz vibrational spectrum. The microscopic origins of this peak are not well understood; the emergence of locally ordered structures has been put forward as a possible candidate. Here, we show that depolarised Raman scattering in liquids consisting of highly symmetric molecules can be used to isolate the boson peak, allowing its detailed observation from the liquid into the glass. The boson peak in the vibrational spectrum matches the excess heat capacity. As the boson peak intensifies on cooling, wide-angle x-ray scattering shows the simultaneous appearance of a pre-peak due to molecular clusters consisting of circa 20 molecules. Atomistic molecular dynamics simulations indicate that these are caused by over-coordinated molecules. These findings represent an essential step toward our understanding of the physics of vitrification.
|
Jan 2023
|
|
I20-EDE-Energy Dispersive EXAFS (EDE)
|
Andrew S.
Leach
,
Jennifer
Hack
,
Monica
Amboage
,
Sofia
Diaz-Moreno
,
Haoliang
Huang
,
Patrick L.
Cullen
,
Martin
Wilding
,
Emanuele
Magliocca
,
Thomas
Miller
,
Christopher
Howard
,
Daniel
Brett
,
Paul
Shearing
,
Paul F.
Mcmillan
,
Andrea E.
Russell
,
Rhodri
Jervis
Diamond Proposal Number(s):
[22008, 15650]
Open Access
Abstract: A polymer electrolyte fuel cell (PEFC) has been designed to allow operando X-ray absorption spectroscopy (XAS) measurements of catalysts. The cell has been developed to operate under standard fuel cell conditions, with elevated temperatures and humidification of the gas-phase reactants, both of which greatly impact the catalyst utilisation. X-ray windows in the endplates of the cell facilitate collection of XAS spectra during fuel cell operation while maintaining good compression in the area of measurement. Results of polarisation curves and cyclic voltammograms (CVs) showed that the operando cell performs well as a fuel cell, while also providing XAS data of suitable quality for robust XANES analysis. The cell has produced comparable XAS results when performing a cyclic voltammogram to an established in situ cell when measuring the Pt LIII edge. Similar trends of Pt oxidation, and reduction of the formed Pt oxide, have been presented with a time resolution of 5 seconds for each spectrum, paving the way for time-resolved spectral measurements of fuel cell catalysts in a fully-operating fuel cell.
|
May 2021
|
|
I15-1-X-ray Pair Distribution Function (XPDF)
|
Diamond Proposal Number(s):
[21208]
Open Access
Abstract: This study combines bulk structural and spectroscopic investigations of Eu3+- or Y3+/Eu3+ co-doped tetragonal and cubic zirconia polymorphs to gain an in-depth understanding of the solid solution formation process. Our bulk structural characterizations show that the dopant is homogenously distributed in the ZrO2 host structure resulting in an increase of the bulk symmetry with increasing dopant substitution (from 8 to 26 mol%). The local site symmetry around the Eu3+ dopant, however, determined with luminescence spectroscopy (TRLFS), remains low in all samples. Results obtained with X-ray pair distribution function and X-ray absorption spectroscopy show that the average coordination environment in the stabilized zirconia structures remains practically unchanged. Despite this very constant average dopant environment, site-selective TRLFS data show the presence of three nonequivalent Eu3+ environments in the ZrO2 solid structures. These Eu3+ environments are assumed to arise from Eu3+ incorporation at superficial sites, which increase in abundance as the size of the crystallites decrease, and incorporation on two bulk sites differing in the location of the oxygen vacancies with respect to the dopant cation.
|
May 2020
|
|
