Electrochemical chlorine evolution at sol-gel derived mixed oxide electrocatalyst coatings

Die Effizienzverbesserung der Elektrodenbeschichtungen spielt eine kritische Rolle bei der Reduzierung des Energieverbrauchs (z.B. der Überspannung) für die elektrolytische Chlorentwicklung. Die Effizienzabhängigkeit der Oxidbeschichtung wurde systematisch in Abhängigkeit von der chemischen Zusammensetzung, der Oberflächenbeschaffenheit und der Phasenstruktur untersucht. Die Multikomponent-Beschichtung RuTiMOx wurde im Sol-Gel Verfahren hergestellt, wobei der Anteil von M=Ir, Sn, V die katalytische Effizienz erheblich verbesserte. Die undurchlässigen und rissfreien Beschichtungen, die durch ein kontrolliertes Beschichten/Trocknen-Verfahren erhalten wurden, sollen die Passivierung des Ti-Substrats verhindern. Es wurden Nano-Poren infolge eines Leaching-Verfahrens aus einer Lantan-haltigen Oxidmatrix erhalten, die eine höchst zugängliche Oberfläche bieten. Mittels einer solvothermalen Kristallisierung des Ru-O-Ti-Xerogels wurde eine neue, in-situ-verstärkte Rutil-RuxTi1-xO2/Anatas-TiO2 Struktur erhalten, die eine erhöhte katalytische Aktivität aufweist. Die Entwicklung der Cl2-Gasblasen auf RuTiMOx/Ti-Elektroden wurde in einem ersten Ansatz durch die Analyse des blaseninduzierten Potentialrauschens mit Hilfe der Wavelet-Transformation untersucht.Performance improvement in electrode coatings plays a critical role in reducing energy consumption (i.e., overpotential) in the electrolytic chlorine production. The performance dependence on the chemical composition, surface morphology and phase structure of the oxide coatings has been investigated systematically. The multi-component RuTiMOx system prepared by the sol-gel route improved effectively the catalytic performance with M = Ir, Sn, V. The impermeable crack-free coatings obtained by controlling the coating/drying process are expected to protect the Ti-substrate against passivation. Nano-pores created by lanthanum leaching from the La-containing oxide matrix provided highly accessible surface. A novel in-situ supported rutile RuTiO2/anatase TiO2 structure with enhanced catalytic activity was achieved by the solvothermal crystallization of the Ru-O-Ti xerogel. Cl2 bubble evolution behaviour at the RuTiMOx/Ti electrodes has been studied in a first approach by analyzing the bubble-induced potential noise using wavelet transform

Redox Flow Batteries: Fundamentals and Applications

A redox flow battery is an electrochemical energy storage device that converts chemical energy into electrical energy through reversible oxidation and reduction of working fluids. The concept was initially conceived in 1970s. Clean and sustainable energy supplied from renewable sources in future requires efficient, reliable and cost‐effective energy storage systems. Due to the flexibility in system design and competence in scaling cost, redox flow batteries are promising in stationary storage of energy from intermittent sources such as solar and wind. This chapter covers basic principles of electrochemistry in redox flow batteries and provides an overview of status and future challenges. Recent progress in redox couples, membranes and electrode materials will be discussed. New demonstration and commercial development will be addressed

Fluorescence quenching and measurement of captopril in pharmaceuticals

The mechanism of fluorescence quenching of the product S in the presence of captopril was studied. The maximum emission wavelength of the product S was at 405 nm with the excitation wavelength at 316 nm. It was found that the fluorescence quenching of product S was of a static one and the binding constant (K) was 9.29 × 106 J mol-1. A linear relationship was found between the relative fluorescence intensity of the product S-captopril system and the concentration of captopril. Under optimum conditions, the linear range of the calibration curve for captopril was 2~160 μg L-1 with a correlation coefficient of 0.9926 and a detection limit of 0.1 μg L-1. The relative standard deviation (RSD) was 3.60%. The analytical results of the pharmaceuticals obtained by this novel method agreed quite well with those obtained by the KIO3 titrimetry

Fluorescence quenching and measurement of captopril in pharmaceuticals

270-276The mechanism of fluorescence quenching of the product S in the presence of captopril was studied. The maximum emission wavelength of the product S was at 405 nm with the excitation wavelength at 316 nm. It was found that the fluorescence quenching of product S was of a static one and the binding constant (K) was 9.29 × 106 J mol-1. A linear relationship was found between the relative fluorescence intensity of the product S-captopril system and the concentration of captopril. Under optimum conditions, the linear range of the calibration curve for captopril was 2~160 μg L-1 with a correlation coefficient of 0.9926 and a detection limit of 0.1 μg L-1. The relative standard deviation (RSD) was 3.60%. The analytical results of the pharmaceuticals obtained by this novel method agreed quite well with those obtained by the KIO3 titrimetry

A behavioral mechanistic investigation of the role of 5-HT\u3csub\u3e1A\u3c/sub\u3e receptors in the mediation of rat maternal behavior

Previous work suggests that 5-HT1A receptors play a special role in rodent maternal aggression, but not in other aspects of maternal care (e.g. pup retrieval and nest building). The present study re-assessed the basic effects of 5-HT1A activation or blockade on various maternal responses in postpartum female rats. We also examined the possible behavioral mechanisms underlying the maternal effects of 5-HT1A. Sprague–Dawley mother rats were injected with a 5-HT1A agonist 8-OH-DPAT (0.1, 0.5 or 1.0 mg/kg, sc), a 5-HT1A antagonist WAY-101405 (0.1, 0.5 or 1.0 mg/kg, sc) or 0.9% saline solution on postpartum days 3, 5, and 7. Maternal behavior was tested 30 min before, 30 min, 120 min, and 240 min after the injection. Acute and repeated 8-OH-DPAT treatment significantly disrupted pup retrieval, pup licking, nursing, and nest building in a dose-dependent fashion, whereas WAY-101405 had no effect at the tested doses. The 5-HT1A receptor specificity of 8-OH-DPAT\u27s action was confirmed as its maternal disruption effect was reversed by pretreatment of WAY-100635 (a highly selective 5-HT1A receptor antagonist). Subsequent pup preference test found that 8-OH-DPAT did not decrease the pup preference over a novel object, thus no inhibition on maternal motivation or maternal affect. The pup separation test and pup retrieval on an elevated plus maze test also failed to find any motivational and motor impairment effect with 8-OH-DPAT. However, 8-OH-DPAT at the maternal disruptive dose did disrupt the prepulse inhibition (a measure of attentional function) of acoustic startle response and enhanced the basal startle response. These findings suggest that stimulation of 5-HT1A receptors by 8-OH-DPAT impairs maternal care by partially interfering with the attentional processing or basal anxiety. More work is needed to further delineate the psychological and neuronal mechanisms underlying the maternal disruptive effect of 5-HT1A receptor activation

Control of Ionic Conductivity by Lithium Distribution in Cubic Oxide Argyrodites Li6+XP1-XSiXO5Cl

Argyrodite is a key structure type for ion-transporting materials. Oxide argyrodites are largely unexplored despite sulfide argyrodites being a leading family of solid-state lithium-ion conductors, in which the control of lithium distribution over a wide range of available sites strongly influences the conductivity. We present a new cubic Li-rich (>6 Li+ per formula unit) oxide argyrodite Li7SiO5Cl that crystallizes with an ordered cubic (P213) structure at room temperature, undergoing a transition at 473 K to a Li+ site disordered F4̅3m structure, consistent with the symmetry adopted by superionic sulfide argyrodites. Four different Li+ sites are occupied in Li7SiO5Cl (T5, T5a, T3, and T4), the combination of which is previously unreported for Li-containing argyrodites. The disordered F4̅3m structure is stabilized to room temperature via substitution of Si4+ with P5+ in Li6+xP1-xSixO5Cl (0.3 x + sites leads to a maximum ionic conductivity of 1.82(1) × 10-6 S cm-1 at x = 0.75, which is 3 orders of magnitude higher than the conductivities reported previously for oxide argyrodites. The variation of ionic conductivity with composition in Li6+xP1-xSixO5Cl is directly connected to structural changes occurring within the Li+ sublattice. These materials present superior atmospheric stability over analogous sulfide argyrodites and are stable against Li metal. The ability to control the ionic conductivity through structure and composition emphasizes the advances that can be made with further research in the open field of oxide argyrodites

Accessing Mg‐Ion Storage in V 2 PS 10 via Combined Cationic‐Anionic Redox with Selective Bond Cleavage

Magnesium batteries attract interest as alternative energy‐storage devices because of elemental abundance and potential for high energy density. Development is limited by the absence of suitable cathodes, associated with poor diffusion kinetics resulting from strong interactions between Mg2+ and the host structure. V2PS10 is reported as a positive electrode material for rechargeable magnesium batteries. Cyclable capacity of 100 mAh g−1 is achieved with fast Mg2+ diffusion of 7.2 × ${\times }$ 10−11–4 × ${\times }$ 10−14 cm2 s−1. The fast insertion mechanism results from combined cationic redox on the V site and anionic redox on the (S2)2− site; enabled by reversible cleavage of S−S bonds, identified by X‐ray photoelectron and X‐ray absorption spectroscopy. Detailed structural characterisation with maximum entropy method analysis, supported by density functional theory and projected density of states analysis, reveals that the sulphur species involved in anion redox are not connected to the transition metal centres, spatially separating the two redox processes. This facilitates fast and reversible Mg insertion in which the nature of the redox process depends on the cation insertion site, creating a synergy between the occupancy of specific Mg sites and the location of the electrons transferred

Superionic lithium transport via multiple coordination environments defined by two-anion packing

Fast cation transport in solids underpins energy storage. Materials design has focused on structures that can define transport pathways with minimal cation coordination change, restricting attention to a small part of chemical space. Motivated by the greater structural diversity of binary intermetallics than that of the metallic elements, we used two anions to build a pathway for three-dimensional superionic lithium ion conductivity that exploits multiple cation coordination environments. Li 7 Si 2 S 7 I is a pure lithium ion conductor created by an ordering of sulphide and iodide that combines elements of hexagonal and cubic close-packing analogously to the structure of NiZr. The resulting diverse network of lithium positions with distinct geometries and anion coordination chemistries affords low barriers to transport, opening a large structural space for high cation conductivity. </jats:p

Ionic liquids-mediated recovery of metals from spent batteries

Tremendous efforts are being made toward electrification of the transport sector. Accordingly, next-generation recycling technologies to tackle the large volumes of spent batteries must be urgently innovated. Herein, ionic liquids and the promising ionometallurgy that can overcome some issues of traditional recycling methods are discussed. Ionic liquids-mediated recovery of metals from spent batteries represents a sustainable strategy, featured with new fundamental chemistries. The opportunities for regeneration and reuse of ionic liquids are promising toward a cost-levelized recycling process. The unique chemical environment of ionic liquids also allows the development of coupled electrochemical procedures and upcycling. Future development requires the assessment of continuous operation and holistic process efficiency, technoeconomic and environmental aspects