A5091793009- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Advancements in Battery Materials
- Electron and X-Ray Spectroscopy Techniques
- Machine Learning in Materials Science
- Advancements in Solid Oxide Fuel Cells
- Electrochemical Analysis and Applications
- CO2 Reduction Techniques and Catalysts
- Advanced Battery Materials and Technologies
- Advanced battery technologies research
- Advanced Battery Technologies Research
- Advanced Electron Microscopy Techniques and Applications
- Catalytic Processes in Materials Science
- Semiconductor materials and devices
- Extraction and Separation Processes
- Molecular Junctions and Nanostructures
- Gas Sensing Nanomaterials and Sensors
- Advanced X-ray Imaging Techniques
- Particle physics theoretical and experimental studies
- Ionic liquids properties and applications
- Particle Detector Development and Performance
- X-ray Diffraction in Crystallography
- Perovskite Materials and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Analytical Chemistry and Sensors
European Synchrotron Radiation Facility
2019-2025
European Science Foundation
2021-2024
University of British Columbia
2014-2021
Elkhorn Slough Foundation
2020
University of Calgary
2011-2016
Cu oxides catalyze the electrochemical carbon dioxide reduction reaction (CO2RR) to hydrocarbons and oxygenates with favorable selectivity. Among them, shape-controlled oxide cubes have been most widely studied. In contrast, we report on novel 2-dimensional (2D) Cu(II) nanosheet (CuO NS) catalysts high C
Stable emission in glass Lead halide perovskites can exhibit bright, narrow band photoluminescence but have stability issues related to formation of inactive phases and the loss lead ions. Hou et al . show that black, photoactive phase cesium iodide be stabilized by forming a composite with glassy metal-organic framework through liquid-phase sintering. The is at least two orders magnitude greater than pure perovskite. stabilizes perovskite under high laser excitation, about 80% was...
Abstract The long-term stability of Pt-based catalysts is critical to the reliability proton exchange membrane fuel cells (PEMFCs), and receives constant attention. However, current knowledge Pt oxidation restricted unrealistic PEMFC cathode environment or operation, which questions its practical relevance. Herein, investigated directly in a with stroboscopic operando high energy X-ray scattering. onset potential for phase transition nanoparticles surface from metallic amorphous...
Cathode catalyst layers of proton exchange membrane fuel cells (PEMFCs) typically consist carbon-supported platinum catalysts with varying weight ratios proton-conducting ionomers. N-Doping carbon support materials is proposed to enhance the performance and durability cathode layer under operating conditions in a PEMFC. However, detailed understanding contributing N-moieties missing. Here, we report successful synthesis cell implementation Pt electrocatalysts supported on N-doped carbons,...
The degradation of Pt-containing oxygen reduction catalysts for fuel cell applications is strongly linked to the electrochemical surface oxidation and Pt. Here, we study restructuring Pt dissolution mechanisms during oxidation/reduction case Pt(100) in 0.1 M HClO4 by combining operando high-energy X-ray diffraction, online mass spectrometry, density functional theory. Our atomic-scale structural studies reveal that anodic dissolution, detected oxidation, cathodic observed subsequent...
Bidentate phosphonate monoesters are analogues of popular dicarboxylate linkers in MOFs, but with an alkoxy tether close to the coordinating site. Herein, we report 3-D MOF materials based upon monoester linkers. Cu(1,4-benzenediphosphonate bis(monoalkyl ester), CuBDPR, ethyl is nonporous; however, methyl generates isomorphous framework that porous and captures CO2 a high isosteric heat adsorption 45 kJ mol–1. Computational modeling reveals uptake extremely sensitive both flexing structure...
The proliferation of hydrogen fuel cell systems is hindered by a degradation the platinum catalyst. Here, we provide device-level assessment catalyst phenomena and its coupling to nanoscale hydration gradients, using advanced operando X-ray scattering tomography tailored for device-scale imaging. Gradients formed inside produce heterogeneous nanostructure, which can be linked flow field design water distribution in cell. Striking differences are observed between operating devices liquid...
Preliminary testing of fuel cell catalysts in a model laboratory environment is an essential step the technology readiness level progression material candidates toward commercial device. However, case platinum alloy for oxygen reduction reaction (ORR) proton exchange membrane cells (PEMFCs), there no consensus on protocol employed catalyst conditioning (activation or break-in), leading to important discrepancies literature. Here, effects electrochemical PtNi nanocatalyst structure, chemical...
Herein, we demonstrate the superior performance of bismuth subcarbonate ((BiO)2CO3) layer catalysts for formate production using a fluidic CO2-fed electrolyzer device. The catalyst readily forms in situ from CO2-absorbing Bi2O3 precursor material during CO2 reduction reaction (CO2RR). In 1 mol dm–3 KOH electrolyte solution, maximum Faradaic efficiency FEformate = 97.4% (corresponding partial current density formation: PCDformate −111.6 mA cm–2) was achieved at comparably low applied...
Abstract The reaction processes in Li‐ion batteries can be highly heterogeneous at the electrode scale, leading to local deviations lithium content or degradation phenomena. To access distribution of lithiated phases throughout a high energy density silicon‐graphite composite anode, correlative operando SAXS and WAXS tomography are applied. In‐plane out‐of‐plane inhomogeneities resolved during cycling moderate rates, as well relaxation steps performed open circuit voltage given states...
ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTBuilding Practical Descriptors for Defect Engineering of Electrocatalytic MaterialsRaphaël Chattot*Raphaël ChattotUniv. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, INP, LEPMI, 38000 Grenoble, FranceEuropean Synchrotron Radiation Facility, ID 31 Beamline, BP 220, F-38043 France*Email R.C.: [email protected]More by Raphaël Chattothttp://orcid.org/0000-0001-6169-530X, Pierre BordetPierre BordetUniv. Institut Néel, F-38000 FranceMore...
The theoretical design of effective metal electrocatalysts for energy conversion and storage devices relies greatly on supposed unilateral effects catalysts structure electrocatalyzed reactions. Here, by using high-energy X-ray diffraction from the new Extremely Brilliant Source European Synchrotron Radiation Facility (ESRF-EBS) device-relevant Pd Pt nanocatalysts during cyclic voltammetry experiments in liquid electrolytes, we reveal near ubiquitous feedback various electrochemical...
A combination of operando small- and wide-angle X-ray scattering is here presented to provide insights into the changes in mean particle sizes phase fractions fuel cell catalyst layers during accelerated stress tests (ASTs). As a catalyst, bimodal Pt/C was chosen that consists two distinguishable size populations. The presence different should favor uncover electrochemical Ostwald ripening as degradation mechanism, is, growth larger particles at expense smaller via formation ionic metal...
Octahedra (oh) PtNiX/C catalysts are notable cathode for proton-exchange membrane fuel cells due to their exceptional oxygen reduction reaction activity. Here, we investigate the degradation of oh-PtNiIr under fuel-cell conditions using operando X-ray diffraction (XRD). Employing two accelerated stress tests with different lower potential limits and XRD-coupled cyclic voltammetry on benchmark Pt catalysts, find that dissolution proportional extent reduction, independent catalyst's nature....
Abstract A study has been performed to understand the effects of radiation damage on various plastic scintillator tiles considered for a possible upgrade hadron calorimeter CMS detector. Measurements were made with unirradiated and that had irradiated in collision hall dose 44 kGy. Results are presented different shapes terms energy spectrum, efficiency as function position at which each tile was hit, well light yield. All showed reduction up about 50%. The shape currently used detector did...
Abstract The nanoscale mechanisms of ion deintercalation in battery cathode materials remain poorly understood, especially the relationship between crystallographic defects (dislocations, small angle grain boundaries, vacancies, etc ), device performance, and durability. In this work, operando scanning X‐ray diffraction microscopy (SXDM) multi‐crystal (MCXD) are used to investigate microstrain lattice tilt inhomogeneities inside Li 1 − x Ni 0.5 Mn 1.5 O 4 particles during electrochemical...
Structural defects are of significant importance in (electro)catalysis, as they provide sites unusually high activity that find applications many key electrochemical processes. However, tools to characterize surface remain scarce and complex, especially for nanocatalysts where classical methods such transmission electron microscopy or X-ray scattering limited their ability probe the structure distribution active sites. Herein, we show ratio between COads stripping charge (QCO) required...
The processes leading to degradation of Pt nanoparticles inside commercial hydrogen fuel cell catalyst layers are studied in situ, using time-resolved high-energy powder X-ray diffraction. Advances electrochemical design significantly increase the quality diffraction patterns obtained at practical loadings high temporal resolution and allow use advanced techniques including differential pair distribution function analysis. Rietveld refinement lattice parameter peak intensities during cyclic...