Sustained Ventricular Tachycardia as the first presentation of transthyretin amyloid cardiomyopathy.

Transthyretin Amyloid Cardiomyopathy (ATTR-CM) was considered an uncommon disease until a few years ago, but advances in the epidemiology and non-invasive diagnostic tests have increased its timely detection. We report a 71 years-old man with history of hypertension and an incidental carcinoma of the left kidney detected 6 years ago, without heart failure who was performed cardiac magnetic resonance images (MRI) by suspicion of hypertrophic cardiomyopathy. Before his cardiologist be aware of the result, he suffered a severe sustained ventricular tachycardia (SVT) that required emergency cardioversion.

Cationic and Anionic Dual Redox Activity of MoS for Electrochemical Potassium Storage.

MoS is regarded as one of the most promising potassium-ion battery (PIB) anodes. Despite the great progress to enhance its electrochemical performance, understanding of the electrochemical mechanism to store K-ions in MoS remains unclear. This work reports that the K storage process in MoS follows a complex reaction pathway involving the conversion reactions of Mo and S, showing both cationic redox activity of Mo and anionic redox activity of S.

Tracking Minority Species in Redox Reactions: A Quantitative Combined XAS and Modulation Excitation Study.

Understanding the nature of intermediates/active species in reactions is a major challenge in chemistry. This is because spectator species typically dominate the experimentally derived data and consequently active phase contributions are masked. Transient methods offer a means to bypass this difficulty.

Water-hydroxide trapping in cobalt tungstate for proton exchange membrane water electrolysis.

The oxygen evolution reaction is the bottleneck to energy-efficient water-based electrolysis for the production of hydrogen and other solar fuels. In proton exchange membrane water electrolysis (PEMWE), precious metals have generally been necessary for the stable catalysis of this reaction. In this work, we report that delamination of cobalt tungstate enables high activity and durability through the stabilization of oxide and water-hydroxide networks of the lattice defects in acid.

Role of Electrolyte pH on Water Oxidation for Iridium Oxides.

Understanding the effect of noncovalent interactions of intermediates at the polarized catalyst-electrolyte interface on water oxidation kinetics is key for designing more active and stable electrocatalysts. Here, we combine optical spectroscopy, X-ray absorption spectroscopy (XAS), and surface-enhanced infrared absorption spectroscopy (SEIRAS) to probe the effect of noncovalent interactions on the oxygen evolution reaction (OER) activity of IrO in acidic and alkaline electrolytes. Our results suggest that the active species for the OER (Ir-*O) binds much stronger in alkaline compared with acid at low coverage, while the repulsive interactions between these species are higher in alkaline electrolytes.

Cooperative Effects Drive Water Oxidation Catalysis in Cobalt Electrocatalysts through the Destabilization of Intermediates.

A barrier to understanding the factors driving catalysis in the oxygen evolution reaction (OER) is understanding multiple overlapping redox transitions in the OER catalysts. The complexity of these transitions obscure the relationship between the coverage of adsorbates and OER kinetics, leading to an experimental challenge in measuring activity descriptors, such as binding energies, as well as adsorbate interactions, which may destabilize intermediates and modulate their binding energies. Herein, we utilize a newly designed optical spectroelectrochemistry system to measure these phenomena in order to contrast the behavior of two electrocatalysts, cobalt oxyhydroxide (CoOOH) and cobalt-iron hexacyanoferrate (cobalt-iron Prussian blue, CoFe-PB).

Activating Mn Sites by Ni Replacement in α-MnO.

Transition metal oxides are characterized by an acute structure and composition dependent electrocatalytic activity toward the oxygen evolution (OER) and oxygen reduction (ORR) reactions. For instance, Mn containing oxides are among the most active ORR catalysts, while Ni based compounds tend to show high activity toward the OER in alkaline solutions. In this study, we show that incorporation of Ni into α-MnO, by adding Ni precursor into the Mn-containing hydrothermal solution, can generate distinctive sites with different electronic configurations and contrasting electrocatalytic activity.

An Atomically Dispersed Mn-Photocatalyst for Generating Hydrogen Peroxide from Seawater via the Water Oxidation Reaction (WOR).

In this work, we have fabricated an aryl amino-substituted graphitic carbon nitride (g-CN) catalyst with atomically dispersed Mn capable of generating hydrogen peroxide (HO) directly from seawater. This new catalyst exhibited excellent reactivity, obtaining up to 2230 μM HO in 7 h from alkaline water and up to 1800 μM from seawater under identical conditions. More importantly, the catalyst was quickly recovered for subsequent reuse without appreciable loss in performance.

Active and durable RMnRuO pyrochlores with low Ru content for acidic oxygen evolution.

The production of green hydrogen in water electrolyzers is limited by the oxygen evolution reaction (OER). State-of-the-art electrocatalysts are based on Ir. Ru electrocatalysts are a suitable alternative provided their performance is improved.

Highly active and stable OER electrocatalysts derived from SrMIrO for proton exchange membrane water electrolyzers.

Proton exchange membrane water electrolysis is a promising technology to produce green hydrogen from renewables, as it can efficiently achieve high current densities. Lowering iridium amount in oxygen evolution reaction electrocatalysts is critical for achieving cost-effective production of green hydrogen. In this work, we develop catalysts from Ir double perovskites.

Correlating Orbital Composition and Activity of LaMnNiO Nanostructures toward Oxygen Electrocatalysis.

The atomistic rationalization of the activity of transition metal oxides toward oxygen electrocatalysis is one of the most complex challenges in the field of electrochemical energy conversion. Transition metal oxides exhibit a wide range of structural and electronic properties, which are acutely dependent on composition and crystal structure. So far, identifying one or several properties of transition metal oxides as descriptors for oxygen electrocatalysis remains elusive.

Insight into the Activity and Selectivity of Nanostructured Copper Titanates during Electrochemical Conversion of CO at Neutral pH via In Situ X-ray Absorption Spectroscopy.

The electrochemical conversion of carbon dioxide (CO) to useful chemical fuels is a promising route toward the achievement of carbon neutral and carbon negative energy technologies. Copper (Cu)- and Cu oxide-derived surfaces are known to electrochemically convert CO to high-value and energy-dense products. However, the nature and stability of oxidized Cu species under reaction conditions are the subject of much debate in the literature.

Contrasting the EXAFS obtained under air and H environments to reveal details of the surface structure of Pt-Sn nanoparticles.

Understanding the surface structure of bimetallic nanoparticles is crucial for heterogeneous catalysis. Although surface contraction has been established in monometallic systems, less is known for bimetallic systems, especially of nanoparticles. In this work, the bond length contraction on the surface of bimetallic nanoparticles is revealed by XAS in H2 at room temperature on dealloyed Pt-Sn nanoparticles, where most Sn atoms were oxidized and segregated to the surface when measured in air.

The Role of Growth Directors in Controlling the Morphology of Hematite Nanorods.

The control of the growth of hematite nanoparticles from iron chloride solutions under hydrothermal conditions in the presence of two different structure promoters has been studied using a range of both structural and spectroscopic techniques including the first report of photo induced force microscopy (PiFM) to map the topographic distribution of the structure-directing agents on the developing nanoparticles. We show that the shape of the nanoparticles can be controlled using the concentration of phosphate ions up to a limit determined to be ~6 × 10 mol. Akaganéite (β-FeOOH) is a major component of the nanoparticles formed in the absence of structure directors but only present in the very early stages (< 8 h) of particle growth when phosphate is present.

Observation of visible light activated photocatalytic degradation of stearic acid on thin films of tantalum oxynitride synthesized by aerosol assisted chemical vapour deposition.

UV activated photocatalysts deposited using chemical vapour deposition have found commercial success as self-cleaning coatings. However, only limited work has been conducted on the use of the more recently discovered visible light activated photocatalysis for this application. Tantalum oxynitride is an established visible light photocatalyst, and in this paper we have investigated the ability of thin films of tantalum oxynitride to photocatalytically degrade a model organic pollutant, stearic acid, and therefore assess the coatings potential for self-cleaning applications.

Evidence for tetranuclear bis-μ-oxo cubane species in molecular iridium-based water oxidation catalysts from XAS analysis.

The structure of a highly active pyridine-alkoxide iridium water oxidation catalyst (WOC) is examined by X-ray absorption spectroscopy (XAS). A detailed comparison with IrO2 points to a rigid molecular unit of low nuclearity, with the best analysis suggesting a novel tetrameric iridium-oxo cubane as the resting state.

Effect of Ba Content on the Activity of La Ba MnO Towards the Oxygen Reduction Reaction.

The electrocatalytic activity of La Ba MnO nanoparticles towards the oxygen reduction reaction (ORR) is investigated as a function of the A-site composition. Phase-pure oxide nanoparticles with a diameter in the range of 40 to 70 nm were prepared by using an ionic liquid route and deposited onto mesoporous carbon films. The structure and surface composition of the nanoparticles are probed by XRD, TEM, EDX, and XPS.

Effects of heat treatment atmosphere on the structure and activity of PtSn nanoparticle electrocatalysts: a characterisation case study.

Comprehensive identification of the phases and atomic configurations of bimetallic nanoparticle catalysts are critical in understanding structure-property relationships in catalysis. However, control of the structure, whilst retaining the same composition, is challenging. Here, the same carbon supported Pt3Sn catalyst is annealed under air, Ar and H2 resulting in variation of the extent of alloying of the two components.

Enhanced MFC power production and struvite recovery by the addition of sea salts to urine.

Urine is an excellent fuel for electricity generation in Microbial Fuel Cells (MFCs), especially with practical implementations in mind. Moreover, urine has a high content in nutrients which can be easily recovered. Struvite (MgNHPO·6HO) crystals naturally precipitate in urine, but this reaction can be enhanced by the introduction of additional magnesium.

Ion flow in a zeolitic imidazolate framework results in ionic diode phenomena.

Ionic transport (for applications in nanofluidics or membranes) and "ionic diode" phenomena in a zeolitic imidazolate framework (ZIF-8) are investigated by directly growing the framework from aqueous Zn(2+) and 2-methylimidazole as an "asymmetric plug" into a 20 μm diameter pore in a ca. 6 μm thin poly-ethylene-terephthalate (PET) film.

Surface activation of Pt nanoparticles synthesised by "hot injection" in the presence of oleylamine.

Oleylamine (OA) based "hot injection" colloidal synthesis offers a versatile approach to the synthesis of highly monodisperse metallic and multi-metallic alloyed nanostructures in the absence of potentially toxic and unstable phosphine compounds. For application in heterogeneous catalysis and electrocatalysis, the adsorbed OA species at the metal surfaces should be effectively removed without compromising the structure and composition of the nanostructures. Herein, we investigate the removal of OA from colloidal Pt nanoparticles through 1) "chemical methods" such as washing in acetic acid or ethanol, and ligand exchange with pyridine; and 2) thermal pre-treatment between 185 and 400 °C in air, H2 or Ar atmospheres.

Tuning CO2 electroreduction efficiency at Pd shells on Au nanocores.

The faradaic efficiency of CO2 electroreduction is significantly affected by the thickness of Pd nanoshells on Au cores. The ratio of hydrogen evolution to CO2 reduction was determined by differential electrochemical mass spectrometry. Decreasing the Pd shell thickness from 10 to 1 nm leads to a twofold increase in faradaic efficiency.

Insulating diamond particles as substrate for Pd electrocatalysts.

The suitability of insulating highly crystalline diamond particles as support for Pd based electrocatalysts is explored for the first time by evaluating the electrochemical stripping of CO and oxidation of formic acid in acid solutions.