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This study reports a facile and reliable operando X‐ray photoelectron spectroscopy (XPS) system for the characterization of the chemical state and electronic structure during Li‐plating/stripping in all‐solid‐state batteries (ASSBs). The measurement conditions (including manufacturing an in situ sample holder) and experimental parameters have been optimized through experimentation. The proposed system accurately defines the status of every metal interlayer component during real‐time battery operation (with simultaneous Li+‐ion in/out migration) under a repeating Li‐plating/stripping process. Moreover, it enables elucidation of ambiguous reaction mechanisms depending on the battery performance, such as the interlayer‐material effect on the efficiency and reversibility of the Li‐plating/stripping process, and changes in the oxygen‐containing bonds due to reaction with Li. The significance of the developed system is further validated by the usefulness and reliability of the valence band structure as a criterion for the analysis of lithium‐metal alloy formation and the progress of de‐alloying reactions. [ABSTRACT FROM AUTHOR]

Metal‐based chalcogenides exhibit great promise for overall water splitting, yet their intrinsic catalytic reaction mechanisms remain to be fully understood. In this work, we employed operando X‐ray absorption (XAS) and in situ Raman spectroscopy to elucidate the structure–activity relationships of low‐crystalline cobalt sulfide (L−CoS) catalysts toward overall water splitting. The operando results for L−CoS catalyzing the alkaline hydrogen evolution reaction (HER) demonstrate that the cobalt centers in the bulk are predominantly coordinated by sulfur atoms, which undergo a kinetic structural rearrangement to generate metallic cobalt in S−Co−Co−S moieties as the true catalytically active species. In comparison, during the acidic HER, L−CoS undergoes local structural optimization of Co centers, and H2 production proceeds with adsorption/desorption of key intermediates atop the Co−S−Co configurations. Further operando characterizations highlight the crucial formation of high‐valent Co4+ species in L−CoS for the alkaline oxygen evolution reaction (OER), and the formation of such active species was found to be far more facile than in crystalline Co3O4 and Co‐LDH references. These insights offer a clear picture of the complexity of active species and site formation in different media, and demonstrate how their restructuring influences the catalytic activity. [ABSTRACT FROM AUTHOR]

Since 20 years, titanium oxide materials and in particular, lithium titanate spinel Li4Ti5O12 (LTO) were considered as promising negative electrode materials for lithium-ion cells. In the case of the TiNb2O7 compound (TNO), which has a larger theoretical lithiation capacity of 388 mAh g−1, few studies have focused on the outgassing of the material. In this work, we quantified the volume produced as a function of different cycling parameters and then characterized the produced species and show a prevalence of H2 gas. The use of carbon coating as a mitigation strategy and its limitation is also discussed. [ABSTRACT FROM AUTHOR]

Although the synthesis of nanoparticles (NPs) by low-pressure plasma-based sputtering onto liquids offers many advantages as compared to classic wet-chemistry-based approaches, not much is known about the nanoparticle formation mechanism in these conditions. Here, we report about an operando absorption spectrophotometry setup which allows recording time- and space-resolved spectra of the liquid into which the sputtered metal atoms are incorporated. The measurements are carried out during the plasma treatment but also afterward while keeping the sample inside the vacuum chamber. The device capabilities therefore allow studying the evolution of unstable systems, i.e., combination of sputtered atoms and host liquids for which aggregation may appear even during the plasma treatment time. As a model system, silver atoms are deposited onto a silicone oil which may be stirred or not. Our operando analysis provides qualitative and quantitative data and highlights that the nanoparticle formation and aggregation dynamics vary according to the process conditions. [ABSTRACT FROM AUTHOR]

The operating principle of a Pt thin-film H2 gas sensor was investigated using a combination of surface sensitive ambient-pressure X-ray photoelectron spectroscopy and bulk sensitive X-ray absorption fine structure techniques, which provided chemical and structure information under working conditions, coupled with electric resistivity measurements. It is shown that the sensor response was in a linear relation with both coverages of H and O atoms on the Pt surface. Moreover, the bulk structure of Pt remains unchanged under H2 exposure. These observations support that the resistivity change is associated with electron scattering in the near-surface region. [ABSTRACT FROM AUTHOR]

Ternary Pd‐In2O3/ZrO2 catalysts exhibit technological potential for CO2‐based methanol synthesis, but developing scalable systems and comprehending complex dynamic behaviors of the active phase, promoter, and carrier are key for achieving high productivity. Here, we show that the structure of Pd‐In2O3/ZrO2 systems prepared by wet impregnation evolves under CO2 hydrogenation conditions into a selective and stable architecture, independent of the order of addition of Pd and In phases on the zirconia carrier. Detailed operando characterization and simulations reveal a rapid restructuring driven by the metal‐metal oxide interaction energetics. The proximity of InPdx alloy particles decorated by InOx layers in the resulting architecture prevents performance losses associated with Pd sintering. The findings highlight the crucial role of reaction‐induced restructuring in complex CO2 hydrogenation catalysts and offer insights into the optimal integration of acid‐base and redox functions for practical implementation. [ABSTRACT FROM AUTHOR]

Nearly half of the elements in the periodic table are extracted, refined, or plated using electrodeposition in high-temperature melts. However, operando observations and tun- ing of the electrodeposition process during realistic electrolysis operations are extremely difficult due to severe reaction conditions and complicated electrolytic cell, which makes the improvement of the process very blind and inefficient. Here, we developed a mul- tipurpose operando high-temperature electrochemical instrument that combines oper- ando Raman microspectroscopy analysis, optical microscopy imaging, and a tunable magnetic field. Subsequently, the electrodeposition of Ti—which is a typical polyvalent metal and generally shows a very complex electrode process—was used to verify the sta- bility of the instrument. The complex multistep cathodic process of Ti in the molten salt at 823 K was systematically analyzed by a multidimensional operando analysis strategy involving multiple experimental studies, theoretical calculations, etc. The regulatory effect and its corresponding scale-span mechanism of the magnetic field on the electro- deposition process of Ti were also elucidated, which would be inaccessible with existing experimental techniques and is significant for the real-time and rational optimization of the process. Overall, this work established a powerful and universal methodology for in- depth analysis of high- temperature electrochemistry. [ABSTRACT FROM AUTHOR]

The reported study was devoted to the investigation of viscoelastic behavior for solid and porous ultra-high molecular weight polyethylene (UHMWPE) under compression. The obtained experimental stress curves were interpreted using a two-term Prony series to represent the superposition of two coexisting activation processes corresponding to long molecular (~160 s) and short structural (~20 s) time scales, respectively, leading to good statistical correlation with the observations. In the case of porous polymer, the internal strain redistribution during relaxation was quantified using digital image correlation (DIC) analysis. The strongly inhomogeneous deformation of the porous polymer was found not to affect the relaxation times. To illustrate the possibility of generalizing the results to three dimensions, X-ray tomography was used to examine the porous structure relaxation at the macro- and micro-scale levels. DIC analysis revealed positive correlation between the applied force and relative density. The apparent stiffness variation for UHMWPE foams with mixed open and closed cells was described using a newly proposed three-term expression. Furthermore, in situ tensile loading and X-ray scattering study was applied for isotropic solid UHMWPE specimens to investigate the evolution of internal structure and orientation during drawing and stress relaxation in another loading mode. [ABSTRACT FROM AUTHOR]

Mechanochemistry has proven to be an excellent green synthesis method for preparing organic, pharmaceutical, and inorganic materials. Mechanocatalysis, inducing a catalytic reaction by mechanical forces, is an emerging field because neither external temperature nor pressure inputs are required. Previous studies reported enhanced catalytic activity during the mechanical treatment of supported gold catalysts for CO oxidation. So far, the processes inside the milling vessel during mechanocatalysis could not be monitored. In this work, the results of high‐energy operando X‐ray powder diffraction experiments and online gas analysis will be reported. A specific milling setup with a custom‐made vessel and gas dosing system was developed. To prove the feasibility of the experimental setup for operando diffraction studies during mechanocatalysis, the CO oxidation with Au@Fe2O3 as a catalyst was selected as a well‐known model reaction. The operando studies enabled monitoring morphology changes of the support as well as changes in the crystallite size of the gold catalyst. The change of the crystal size is directly correlated to changes in the active surface area and thus to the CO2 yield. The studies confirm the successful implementation of the operando setup, and its potential to be applied to other catalytic reactions. [ABSTRACT FROM AUTHOR]

The copper‐zinc‐alumina (CZA) catalyst is one of the most important catalysts. Nevertheless, understanding of the complex CZA structure is still limited and hampers further optimization. Critical to the production of a highly active and stable catalyst are optimal start‐up procedures in hydrogen. Here, by employing operando X‐ray absorption spectroscopy and X‐ray diffraction, we follow how the industrial CZA precursor evolves into the working catalyst. Two major events in the activation drastically alter the copper‐ and zinc‐containing components in the CZA catalyst and define the final working catalyst structure: the reduction of the starting copper(II) oxide, and the ripening and re‐oxidation of zinc oxide upon the switch to catalytic conditions. These drastic events are also accompanied by other gradual, structural changes. Understanding what happens during these events is key to develop tailored start‐up protocols that are aimed at maximal longevity and activity of the catalysts. [ABSTRACT FROM AUTHOR]

Electrochemical dilatometry is used to investigate Li plating/stripping on Cu foil and porous carbon paper substrates. Experiments are performed in standard electrolyte for Li–S batteries at a current density of 1 mA cm−2 with a Li plating charge fixed at 1 mAh cm−2. A fully dense Li film (4.8 μm thick) is initially electrodeposited on the Cu electrode. However, from the 2nd Li plating/stripping cycle, Li deposit becomes porous to reach a thickness of 9.6 µm at the 27th cycle, corresponding to a film porosity of 50%, favoring its collapse during the subsequent cycles. When a carbon paper with a low surface area (0.02 m2 g−1) is used as a substrate, Li deposition occurs preferentially in the pores of the carbon paper during the first few cycles. However, this does not prevent the formation of Li dendrites, which progressively extend on the top of the substrate, resulting in the degradation of the electrode cyclability after about 40 cycles. The use of a carbon paper with a higher surface area (4.2 m2 g−1) favors Li deposition inside the electrode, with no apparent loss of cyclability after 50 cycles. However, this does not prevent the formation of dead Li, as suggested by the continuous and irreversible expansion of the electrode over cycling at a mean rate of 1.3 μm per cycle. Additionally, a large and irreversible expansion of 38 μm is observed during the first cycle, which is attributed to the lithium-solvent co-intercalation in the graphitic part of the carbon paper substrate. [ABSTRACT FROM AUTHOR]

The reported study was devoted to the investigation of viscoelastic behavior for solid and porous ultra-high molecular weight polyethylene (UHMWPE) under compression. The obtained experimental stress curves were interpreted using a two-term Prony series to represent the superposition of two coexisting activation processes corresponding to long molecular (~160 s) and short structural (~20 s) time scales, respectively, leading to good statistical correlation with the observations. In the case of porous polymer, the internal strain redistribution during relaxation was quantified using digital image correlation (DIC) analysis. The strongly inhomogeneous deformation of the porous polymer was found not to affect the relaxation times. To illustrate the possibility of generalizing the results to three dimensions, X-ray tomography was used to examine the porous structure relaxation at the macro- and micro-scale levels. DIC analysis revealed positive correlation between the applied force and relative density. The apparent stiffness variation for UHMWPE foams with mixed open and closed cells was described using a newly proposed three-term expression. Furthermore, in situ tensile loading and X-ray scattering study was applied for isotropic solid UHMWPE specimens to investigate the evolution of internal structure and orientation during drawing and stress relaxation in another loading mode.

Although a semiconductor gas sensor is promising in the future gas sensing technology, the material design for highly sensitive and selective gas sensing is quite challenging. The crystal plane dependence of gas sensing has been studied using various nano‐crystal samples with a controlled crystal facet to obtain a clue for designing the sensing material, but the contact effect between nano‐crystal particles has often hindered the straightforward analysis. In the present study, the crystal plane dependence of ethanol (EtOH) sensing by ZnO, one of the most widely studied target gas‐sensing material combinations, was investigated from an analytical approach. We applied a newly developed low‐energy He+ ion scattering spectroscopy (He+ LEIS) combined with the pulsed jet technique for analyzing the surface structure of ZnO during the EtOH sensing. In this novel technique, the free gas jet is periodically blown onto the sample surface to simulate the gas‐sensing surface in a vacuum as one under the realistic working condition, while the background pressure is maintained low enough for operating He+ LEIS. It was found that the divalent oxygen adatom on the outermost surface is consumed during the EtOH sensing while no change occurs in the concentration of the lattice oxygen on the Zn‐terminated (0001) surface. The availability of this oxygen adsorbate determines the dissociative EtOH adsorption probability on the surface; hence it determines the EtOH sensing sensitivity, which is substantially higher on Zn‐terminated (0001) than other dominant low‐index surfaces, such as O‐terminated (000 1‾), (10 1‾ 0), and (11 2‾ 0). [ABSTRACT FROM AUTHOR]

The internal temperature of a Li-ion battery is one of the critical parameters for monitoring cell performance, ageing and safety. The development of new sensor technologies to control the internal temperature of cells without compromising performance and safety remains a challenge. It is one of the objectives of the European INSTABAT project in the framework of the Battery2030+ initiative. The objective of this paper is to describe the development of a new optical fibre sensor based on a thermoluminescent material to monitor internal cell temperature. The development of the sensor, its thermal characterisation and its calibration are presented here. This sensor was inserted into a commercial Li-ion cell and its response during cycling at high charge and discharge rates (2C in charge and 4C in discharge) was investigated. The comparison between external and internal temperature measurements shows good agreement. These results demonstrate the ability of this type of sensor to monitor the internal temperature of a Li-ion battery without affecting its performance at high loading. [Display omitted] • Thermo-luminescent optical fibre sensor. • Smart cell with embedded optical sensor. • Li-ion battery internal temperature monitoring. • In-situ operando monitoring. [ABSTRACT FROM AUTHOR]

Structural dynamics of a Mn‐Na2WO4/SiO2 catalyst were detected directly under reaction conditions during the oxidative coupling of methane via in situ XRD and operando Raman spectroscopy. A new concept of fluctuating storage and release of an active phase in heterogeneous catalysis is proposed that involves the transient generation of active sodium oxide species via a reversible reaction of Na2WO4 with Mn7SiO12. The process is enabled by phase transitions and melting at the high reaction temperatures that are typically applied. [ABSTRACT FROM AUTHOR]

Starvation, flooding, and dry‐out phenomena occur in polymer electrolyte membrane fuel cells (PEMFCs), due to heterogeneous local conditions, material inhomogeneity, and uneven flow distribution across the single cell active area and in between the individual cells. The impact of the load level and air feed conditions on the performance was identified for individual single cells within a 10‐cell stack. Analysis of the current density distribution across the active area at the cell level was correlated with electrochemical impedance spectroscopy to enable operando fault diagnostic without any impact of the applied analytical tools on the single cell behavior. Moreover, the combination of both technologies allows in‐depth analysis of fault mechanisms in fuel cell single cells with improved sensitivity. Current density distribution and the quantitative assessment of the performance homogeneity demonstrated high sensitivity to small humidity changes and allow the detection of critical events, such as dry‐out in single cells. Impedance analysis is more sensitive regarding polarization and diffusion limitations and allows detection of cell flooding. The combination of both techniques is required for reliable identification of air starvation faults. [ABSTRACT FROM AUTHOR]

Operando analyses have provided several breakthroughs in the construction of high‐performance materials and devices, including energy storage systems. However, despite the advances in electrode engineering, the formidable issues of lithium intercalation and deintercalation kinetics cannot be investigated by using planar observations. This study concerns side‐view operando observation by optical microscopy of a graphite anode based on its color changes during electrochemical lithiation. Since the graphite color varies according to the optical energy gap during lithiation and delithiation, this technique can be used to study the corresponding charge–discharge kinetics. In addition, the cell configuration uses liquid electrolytes similar to commercial cells, allowing practical application. Furthermore, this side‐view observation has shown that microscale spatial variations in rate and composition control the insertion and deinsertion, revealing the kinetics throughout the whole electrode. The results of this study could enhance the fundamental understanding of the kinetics of battery materials. [ABSTRACT FROM AUTHOR]

It is generally believed that CO2 electroreduction to multi‐carbon products such as ethanol or ethylene may be catalyzed with significant yield only on metallic copper surfaces, implying large ensembles of copper atoms. Here, we report on an inexpensive Cu‐N‐C material prepared via a simple pyrolytic route that exclusively feature single copper atoms with a CuN4 coordination environment, atomically dispersed in a nitrogen‐doped conductive carbon matrix. This material achieves aqueous CO2 electroreduction to ethanol at a Faradaic yield of 55 % under optimized conditions (electrolyte: 0.1 m CsHCO3, potential: −1.2 V vs. RHE and gas‐phase recycling set up), as well as CO electroreduction to C2‐products (ethanol and ethylene) with a Faradaic yield of 80 %. During electrolysis the isolated sites transiently convert into metallic copper nanoparticles, as shown by operando XAS analysis, which are likely to be the catalytically active species. Remarkably, this process is reversible and the initial material is recovered intact after electrolysis. [ABSTRACT FROM AUTHOR]

We developed a 3D electrochemical model for simulating the electrochemical properties and revealing the internal properties of a single LiFePO 4 secondary particle during cycling. The main model parameters, such as the diffusion coefficient and rate constant, were optimized using rate capability data, which have been measured experimentally with a unique single particle measurement technique. We simulated voltage profiles at different c-rates from 2 to 20C, which were approximately equivalent to the experimental voltage profiles. The model estimated real-time overpotential, lithium ion concentration, and state-of-charge within the single particle, which have not been obtained experimentally, while changing design parameters and operating conditions. We validated the reliability and applicability of the model by comparing and analyzing the electrochemical results of various LiFePO 4 secondary particles with variable design parameters (i.e., solid volume fraction, secondary particle size, and primary particle size). This graphics illustrates a 24 μm LiFePO4 secondary particle consisting of millions of primary particles of 100–200 nm in diameter. We propose a 3D electrochemical model for simulating the electrochemical properties and unveiling the internal properties of the single particle while changing both particle design parameters and operating conditions. Image 1 • A single LiFePO 4 secondary particle shows high capacity retention at high C-rate. • The particle was modeled with reflecting the experimental conditions. • Performance can be easily predicted by different design parameters using simulation tool. • Internal properties of a single particle were observed, which cannot be measured by experimental methods. [ABSTRACT FROM AUTHOR]

Three‐dimensional imaging using X‐ray as a probe is state‐of‐the‐art for the characterization of heterogeneous materials. In addition to simple imaging of sample morphology, imaging of elemental distribution and chemical states provides advanced maps of key structural parameters of functional materials. The combination of X‐ray absorption fine structure (XAFS) spectroscopy and three‐dimensional imaging such as computed tomography (CT) can visualize the three‐dimensional distribution of target elements, their valence states, and local structures in a non‐destructive manner. In this personal account, our recent results on the three‐dimensional XAFS imaging for Pt cathode catalysts in the membrane electrode assembly (MEA) of polymer electrolyte fuel cell (PEFC) are introduced. The distribution and chemical states of Pt cathode catalysts in MEAs remarkably change under PEFC operating conditions, and the 3D XAFS imaging revealed essential events in PEFC MEAs. [ABSTRACT FROM AUTHOR]

Latest advances on operando analysis in the field of next‐generation battery research are highlighted by means of three examples: recording the pressure change and performing X‐ray diffraction analysis of metal‐oxygen batteries allows to gain detailed understanding of the main reactions and side reactions; analyzing a solid electrolyte in a hot‐press setup allows to monitor crystallization and stability during its synthesis. Since batteries are (electro)chemical reactors, the benefit of using the introduced operando techniques for classical reaction engineering is highlighted thereof. [ABSTRACT FROM AUTHOR]

Renewable technologies, and in particular the electric vehicle revolution, have generated tremendous pressure for the improvement of lithium ion battery performance. To meet the increasingly high market demand, challenges include improving the energy density, extending cycle life and enhancing safety. In order to address these issues, a deep understanding of both the physical and chemical changes of battery materials under working conditions is crucial for linking degradation processes to their origins in material properties and their electrochemical signatures. In situ and operando synchrotron-based X-ray techniques provide powerful tools for battery materials research, allowing a deep understanding of structural evolution, redox processes and transport properties during cycling. In this review, in situ synchrotron-based X-ray diffraction methods are discussed in detail with an emphasis on recent advancements in improving the spatial and temporal resolution. The experimental approaches reviewed here include cell designs and materials, as well as beamline experimental setup details. Finally, future challenges and opportunities for battery technologies are discussed.

Developing scalable systems and understanding dynamic behaviors are crucial for advancing the technological potential of multicomponent catalysts for CO2‐based methanol synthesis. In their Research Article (e202306563), Javier Pérez‐Ramírez and co‐workers show that the reaction‐induced restructuring of Pd‐In2O3/ZrO2 systems, prepared via impregnation, leads to a unique architecture that integrates the necessary acid‐base functionality of In2O3 with the H2 splitting ability of an InPd2 alloy, while also ensuring high stability. [ABSTRACT FROM AUTHOR]

Ternary Pd-In 2 O 3 /ZrO 2 catalysts exhibit technological potential for CO 2 -based methanol synthesis, but developing scalable systems and comprehending complex dynamic behaviors of the active phase, promoter, and carrier are key for achieving high productivity. Here, we show that the structure of Pd-In 2 O 3 /ZrO 2 systems prepared by wet impregnation evolves under CO 2 hydrogenation conditions into a selective and stable architecture, independent of the order of addition of Pd and In phases on the zirconia carrier. Detailed operando characterization and simulations reveal a rapid restructuring driven by the metal-metal oxide interaction energetics. The proximity of InPd x alloy particles decorated by InO x layers in the resulting architecture prevents performance losses associated with Pd sintering. The findings highlight the crucial role of reaction-induced restructuring in complex CO 2 hydrogenation catalysts and offer insights into the optimal integration of acid-base and redox functions for practical implementation., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

A wide variety of analytical methods are used for studying the behavior of lithium-ion batteries and particularly the lithium ion distribution in the electrodes. However, the development of in situ / operando techniques proved powerful to understand the mechanisms responsible for the lithium trapping and then the aging phenomenon. Herein, we report the design of an electrochemical cell to profile operando lithium concentration in LiFePO 4 electrodes using Ion Beam Analysis techniques. The specificity of the cell resides in its ability to not only provide qualitative information about the elements present but above all to measure quantitatively their content in the electrode at different states of charge of the battery. The nuclear methods give direct information about the degradation of the electrolyte and particularly reveal inhomogeneous distributions of lithium and fluorine along the entire thickness of the electrode. Higher concentrations of fluorine is detected near the electrode/electrolyte interface while a depletion of lithium is observed near the current collector at high states of charge. [ABSTRACT FROM AUTHOR]

Nearly half of the elements in the periodic table are extracted, refined, or plated using electrodeposition in high-temperature melts. However, operando observations and tuning of the electrodeposition process during realistic electrolysis operations are extremely difficult due to severe reaction conditions and complicated electrolytic cell, which makes the improvement of the process very blind and inefficient. Here, we developed a multipurpose operando high-temperature electrochemical instrument that combines operando Raman microspectroscopy analysis, optical microscopy imaging, and a tunable magnetic field. Subsequently, the electrodeposition of Ti-which is a typical polyvalent metal and generally shows a very complex electrode process-was used to verify the stability of the instrument. The complex multistep cathodic process of Ti in the molten salt at 823 K was systematically analyzed by a multidimensional operando analysis strategy involving multiple experimental studies, theoretical calculations, etc. The regulatory effect and its corresponding scale-span mechanism of the magnetic field on the electrodeposition process of Ti were also elucidated, which would be inaccessible with existing experimental techniques and is significant for the real-time and rational optimization of the process. Overall, this work established a powerful and universal methodology for in-depth analysis of high-temperature electrochemistry.

Identifying the active sites and their dynamic changes is of critical significance for designing efficient oxygen evolution reaction (OER) catalysts, but remains challenging owing to the complexity in structure and reaction process. Herein, using various operando characterizations, we identify the origin of a 12-time enhancement of OER activity over pure cobalt oxyhydroxide achieved by confining high-valance chromium into its lattice. Operando X-ray absorption spectroscopy reveals in-situ generation of high-valence Cr state with shortened Cr O bond relative to original state, indicating potential-dependent formation of OER intermediates on Cr sites. Operando electrochemical impedance and infrared spectroscopy provide direct spectroscopic evidence of OOH* on Cr site. Combined with theoretical calculations, the confined Cr is identified as the active site with improved bonding strength with O*, exhibiting a lower overpotential than that on Co site. This study elucidates the dynamic behaviour of active sites and provides guiding for improving OER catalysts via introducing high-valance metals. Layered cobalt oxyhydroxide showed a 12-fold OER activity enhancement after confining chromium. Various operando characterizations revealed the potential-relevant electronic and structural dynamics of Co and Cr under realistic working conditions, identifying that high-valence Cr is the active site with moderate bond strength with reaction intermediates. [Display omitted] • The origin of a 12-time OER activity enhancement is identified by various operando characterizations. • Operando electrochemical impedance and X-ray absorption spectroscopy reveal the dynamic evolutions of the Co and Cr sites. • Operando infrared spectroscopy provide direct spectroscopic evidence of OOH* intermediates on Cr site. • High-valence Cr is identified as the active site with moderate bond strength with reaction intermediates. [ABSTRACT FROM AUTHOR]

To investigate how exhaust heat from automobiles can be converted to renewable energy, an innovative electrothermodynamic cycle is presented, which is based on temporal temperature variations, the pyroelectric effect, instead of spatial temperature gradient, and the Seebeck effect. A generating mechanism is investigated using operando time‐resolved synchrotron X‐ray diffraction. Practical energy and true energy breakeven are achieved via real engine dynamometer experiments. [ABSTRACT FROM AUTHOR]

By using operando Raman spectroscopy (ORS), we investigated the panoramic structure evolution of an iron oxide (α-Fe2O3) catalyst, which is used for the production of olefins via Fischer-Tropsch (FTO). During activation in different atmospheres and reaction at 260 °C and 3.0 MPa, α-Fe2O3 was only partially transformed into γ-Fe2O3 by H2 pretreatment; meanwhile, a transformation of α-Fe2O3→γ-Fe2O3→Fe3O4→Fe5C2 was observed in both CO and syngas (H2/CO). Combining with other techniques such as XRD, TEM, XPS and TPSR, we reveal that assembles of various iron oxides (γ-Fe2O3, Fe3O4, Fe carbide, and their combinations) are responsible for FTO. Especially, the preliminary relationship of catalyst structure and performance relating to the production of olefins directly from syngas was established. Such a study is critical for further understanding of the FTO reaction and other catalytic reactions. [ABSTRACT FROM AUTHOR]

Keywords: Activation; CO2 Conversion; Copper; operando Analysis; Zinc EN Activation CO2 Conversion Copper operando Analysis Zinc 1 1 1 03/30/22 20220404 NES 220404 B Copper and zinc oxide b are a dream team in transforming carbon dioxide and carbon monoxide together with hydrogen into the valuable base chemical methanol. Inspired by the cover art of the music masterpiece "Wish you were here" by Pink Floyd, the picture featuring the Research Article (e202200301) by Jeroen A. van Bokhoven and co-workers highlights the fundamental collaboration of the copper and zinc oxide phase in methanol catalysts for a sustainable future. Inside Cover: Drastic Events and Gradual Change Define the Structure of an Active Copper-Zinc-Alumina Catalyst for Methanol Synthesis (Angew. [Extracted from the article]