Precision of Radiation Chemistry Networks: Playing Jenga with Kinetic Models for Liquid-Phase Electron Microscopy.

Liquid-phase transmission electron microscopy (LP-TEM) is a powerful tool to gain unique insights into dynamics at the nanoscale. The electron probe, however, can induce significant beam effects that often alter observed phenomena such as radiolysis of the aqueous phase. The magnitude of beam-induced radiolysis can be assessed by means of radiation chemistry simulations potentially enabling quantitative application of LP-TEM.

Model Catalytic Studies on the Thermal Dehydrogenation of the Benzaldehyde/Cyclohexylmethanol LOHC System on Pt(111).

We investigated the dehydrogenation reaction and the thermal robustness of the liquid organic hydrogen carrier (LOHC) couple benzaldehyde/cyclohexylmethanol on a Pt(111) model catalyst in situ in synchrotron radiation photoelectron spectroscopy- and complementary temperature-programmed desorption experiments. The system stores hydrogen in a cyclohexyl group and a primary alcohol functionality and achieves an attractive hydrogen storage capacity of 7.0 mass %.

In-Situ Electrolyte for Electrosynthesis: Scalable Anodically-Enabled One-Pot Sequence from Aldehyde to Isoxazol(in)es.

Electrochemical transformations are considered a green alternative to classical redox chemistry as it eliminates the necessity for toxic and waste producing redox reagents. Typical electrochemical reactions require the addition of a supporting electrolyte - an ionic compound to facilitate reaction medium conductivity. However, this is often accompanied by an increase in the amount of produced waste.

Sulfonamide-Sulfonimide Copolymers as Novel, Fluorine-Lean Type of Proton Exchange Membranes for Fuel Cell Application.

In this work, a novel type of fluorine-lean proton exchange membranes is presented, using sulfonamide-sulfonimide functional groups for ion conduction. These groups are constructed on a polystyrene backbone for simple and cost-efficient usage as well as rapid scalability. The polymer is further tailored by adjusting the sulfonamide functionality with various end-groups, namely pentafluorophenyl, 4-fluorophenyl, butyl and octyl groups.

Catalyst durability in electrocatalytic HO production: key factors and challenges.

On-demand electrocatalytic hydrogen peroxide (HO) production is a significant technological advancement that offers a promising alternative to the traditional anthraquinone process. This approach leverages electrocatalysts for the selective reduction of oxygen through a two-electron transfer mechanism (ORR-2e), holding great promise for delivering a sustainable and economically efficient means of HO production. However, the harsh operating conditions during the electrochemical HO production lead to the degradation of both structural integrity and catalytic efficacy in these materials.

Stability of Bimetallic PtRu - From Model Surfaces to Nanoparticulate Electrocatalysts.

Fundamental research campaigns in electrocatalysis often involve the use of model systems, such as single crystals or magnetron-sputtered thin films (single metals or metal alloys). The downsides of these approaches are that oftentimes only a limited number of compositions are picked and tested (guided by chemical intuition) and that the validity of trends is not verified under operating conditions typically present in real devices. These together can lead to deficient conclusions, hampering the direct application of newly discovered systems in real devices.

The Role of Alkali Cations on the Selectivity of 5-Hydroxymethylfurfural Electroreduction on Glassy Carbon.

In the past decade, organic electrosynthesis has emerged as an atom- and energy-efficient strategy for harvesting renewable electricity that provides exceptional control over the reaction parameters. A profound and fundamental understanding of electrochemical interfaces becomes imperative to advance the knowledge-based development of electrochemical processes. The major strategy toward an efficient electrochemical system is based on the advancement in material science for electrocatalysis.

Kinetics of dehydrogenation of -heptane over GaPt supported catalytically active liquid metal solutions (SCALMS).

The concept of Supported Catalytically Active Liquid Metal Solutions (SCALMS) was explored for the catalytic dehydrogenation of -heptane. For this purpose, a GaPt on alumina (GaPt/AlO) was compared with a Pt on alumina catalyst at different reaction temperatures and feed compositions. While the observed activation energies with both catalysts for the overall -heptane depletion rate were similar with both catalysts, the SCALMS systems provides a lower activation energy for the desired dehydrogenation path and significantly higher activation energies for the undesired aromatization and cracking reaction.

Allotrope-dependent activity-stability relationships of molybdenum sulfide hydrogen evolution electrocatalysts.

Molybdenum disulfide (MoS) is widely regarded as a competitive hydrogen evolution reaction (HER) catalyst to replace platinum in proton exchange membrane water electrolysers (PEMWEs). Despite the extensive knowledge of its HER activity, stability insights under HER operation are scarce. This is paramount to ensure long-term operation of Pt-free PEMWEs, and gain full understanding on the electrocatalytically-induced processes responsible for HER active site generation.

Applicability of Single-Layer Graphene as a Hydrogen-Blocking Interlayer in Low-Temperature PEMFCs.

Gas crossover is critical in proton exchange membrane (PEM)-based electrochemical systems. Recently, single-layer graphene (SLG) has gained great research interest due to its outstanding properties as a barrier layer for small molecules like hydrogen. However, the applicability of SLG as a gas-blocking interlayer in PEMs has yet to be fully understood.

Structural Evolution of GaO-Shell and Intermetallic Phases in Ga-Pt Supported Catalytically Active Liquid Metal Solutions.

We present a comprehensive scale-bridging characterization approach for supported catalytically active liquid metal solutions (SCALMS) which combines lab-based X-ray microscopy, nano X-ray computed tomography (nano-CT), and correlative analytical transmission electron microscopy. SCALMS catalysts consist of low-melting alloy particles and have demonstrated high catalytic activity, selectivity, and long-term stability in propane dehydrogenation (PDH). We established an identical-location nano-CT workflow which allows us to reveal site-specific changes of Ga-Pt SCALMS before and after PDH.

Toward High-Energy-Density Fuels for Direct Liquid Organic Hydrogen Carrier Fuel Cells: Electrooxidation of 1-Cyclohexylethanol.

Electrochemically active liquid organic hydrogen carriers (EC-LOHCs) can be used directly in fuel cells; so far, however, they have rather low hydrogen storage capacities. In this work, we study the electrooxidation of a potential EC-LOHC with increased energy density, 1-cyclohexylethanol, which consists of two storage functionalities (a secondary alcohol and a cyclohexyl group). We investigated the product spectrum on low-index Pt single-crystal surfaces in an acidic environment by combining cyclic voltammetry, chronoamperometry, and in situ infrared spectroscopy, supported by density functional theory.

Local electroneutrality breakdown for electrolytes within varying-section nanopores.

We determine the local charge dynamics of a [Formula: see text] electrolyte embedded in a varying-section channel. By means of an expansion based on the length scale separation between the axial and transverse direction of the channel, we derive closed formulas for the local excess charge for both, dielectric and conducting walls, in 2D (planar geometry) as well as in 3D (cylindrical geometry). Our results show that, even at equilibrium, the local charge electroneutrality is broken whenever the section of the channel is not homogeneous for both dielectric and conducting walls as well as for 2D and 3D channels.

Low-Temperature controlled synthesis of nanocast mixed metal oxide spinels for enhanced OER activity.

The controlled cation substitution is an effective strategy for optimizing the density of states and enhancing the electrocatalytic activity of transition metal oxide catalysts for water splitting. However, achieving tailored mesoporosity while maintaining elemental homogeneity and phase purity remains a significant challenge, especially when aiming for complex multi-metal oxides. In this study, we utilized a one-step impregnation nanocasting method for synthesizing mesoporous Mn-, Fe-, and Ni-substituted cobalt spinel oxide (MnFeNiCoO, MFNCO) and demonstrate the benefits of low-temperature calcination within a semi-sealed container at 150-200 °C.

Ga-Pt supported catalytically active liquid metal solutions (SCALMS) prepared by ultrasonication - influence of synthesis conditions on -heptane dehydrogenation performance.

Supported catalytically active liquid metal solution (SCALMS) materials represent a recently developed class of heterogeneous catalysts, where the catalytic reaction takes place at the highly dynamic interface of supported liquid alloys. Ga nuggets were dispersed into nano-droplets in propan-2-ol using ultrasonication followed by the addition of Pt in a galvanic displacement reaction - either directly into the Ga/propan-2-ol dispersion () or consecutively onto the supported Ga droplets (). The galvanic displacement reaction between Ga and Pt was studied in three different reaction media, namely propan-2-ol, water, and 20 vol% water containing propan-2-ol.

Novel side chain functionalized polystyrene/O-PBI blends with high alkaline stability for anion exchange membrane water electrolysis (AEMWE).

We report the synthesis of a polystyrene-based anion exchange polymer bearing the cationic charge at a C6-spacer. The polymer is prepared by a functionalized monomer strategy. First, a copper halide catalyzed C-C coupling reaction between a styryl Grignard and 1,6-dibromohexane is applied, followed by quaternization with -methylpiperidine and free radical polymerization.

Stability of high-entropy alloys under electrocatalytic conditions.

High-entropy alloys are claimed to possess superior stability due to thermodynamic contributions. However, this statement mostly lies on a hypothetical basis. In this study, we use on-line inductively coupled plasma mass spectrometer to investigate the dissolution of five representative electrocatalysts in acidic and alkaline media and a wide potential window targeting the most important applications.

Contribution of Electrolyte Decomposition Products and the Effect of Temperature on the Dissolution of Transition Metals from Cathode Materials.

A fundamental understanding of aging processes in lithium-ion batteries (LIBs) is imperative in the development of future battery architectures for widespread electrification. Herein, dissolution of transition metals from cathode active materials of LIBs is among the most important degradation processes. Research has demonstrated that elevated operating temperatures accelerate battery degradation.

Entropy by Neighbor Distance as a New Measure for Characterizing Spatiotemporal Orders in Microscopic Collective Systems.

Collective systems self-organize to form globally ordered spatiotemporal patterns. Finding appropriate measures to characterize the order in these patterns will contribute to our understanding of the principles of self-organization in all collective systems. Here we examine a new measure based on the entropy of the neighbor distance distributions in the characterization of collective patterns.

Effects of Iron Species on Low Temperature CO Electrolyzers.

Electrochemical energy conversion devices are considered key in reducing CO emissions and significant efforts are being applied to accelerate device development. Unlike other technologies, low temperature electrolyzers have the ability to directly convert CO into a range of value-added chemicals. To make them commercially viable, however, device efficiency and durability must be increased.

Correlating Optical Microspectroscopy with 4×4 Transfer Matrix Modeling for Characterizing Birefringent Van der Waals Materials.

Van der Waals materials exhibit intriguing properties for future electronic and optoelectronic devices. As those unique features strongly depend on the materials' thickness, it has to be accessed precisely for tailoring the performance of a specific device. In this study, a nondestructive and technologically easily implementable approach for accurate thickness determination of birefringent layered materials is introduced by combining optical reflectance measurements with a modular model comprising a 4×4 transfer matrix method and the optical components relevant to light microspectroscopy.