Harvesting chlorine from seawater through electrocatalysis

The production of pharmaceuticals and disinfection goods relies on the availability of chlorine. In a recent Nature Communications article, Liu et al. report on the electrosynthesis of chlorine from seawater-like solutions through a stable and selective Ru-based single-atom catalyst with low overpotential

Квир-лингвистика: нужна ли она отечественной лингвистической гендерологии?

Статья посвящена квир-лингвистике как новому магистральному направлению развития современной парадигмы гендерных исследований. Подробно разбирается концептуальный аппарат этого направления. Описывается попытка изучения фрагментов языкового сознания носителей русского языка с учетом квир-фактора.Стаття присвячена квір-лінгвістиці як новому магістральному напрямку в розвитку сучасної парадигми гендерних досліджень. Докладно розбирається концептуальний апарат цього напрямку. Описується спроба вивчення фрагментів мовної свідомості носіїв російської мови з урахуванням квір-фактору.The article is targeted at a new discipline in the area of gender and language research – queer linguistics. The conceptual linguistic apparatus and terminology are discussed. The study of verbal responses obtained from Russian –speaking informants (gays and lesbians) as a linguistic construal of their world is analyzed

A theoretical and experimental spectroscopy study on methanol and ethanol conversion over H-SAPO-34

The elucidation of the structure-activity relation of zeolites or zeotype materials remains very challenging. Recent advances in both theoretical and experimental techniques provide new opportunities to study these complex materials and any catalytic reaction occurring inside. In order to establish new active reaction routes, the knowledge of formed intermediates is crucial. The characterization of such intermediates can be done using a variety of spectroscopic techniques. In this contribution, methanol and ethanol conversion over H-SAPO-34 is investigated using IR and UV-VIS measurements. Calculated adsorption enthalpies of methanol and ethanol in a large SAPO 44T finite cluster show the stronger adsorption of the larger alcohol by 14 kJ mol-1. Dispersion contributions are found to be crucial. IR spectra are calculated for the clusters containing the adsorbed alcohols and matched with experimental data. In addition, the cluster is also loaded with singly methylated cationic hydrocarbons as these are representative reaction intermediates. A detailed normal mode analysis is performed, enabling to separate the framework-guest contributions. Based on the computed data in situ DRIFT experimental peaks could be assigned. Finally, contemporary DFT functionals such as CAM-B3LYP seem promising to compute gas phase UV-VIS spectra

Emerging analytical methods to characterize zeolite-based materials

Zeolites and zeolitic materials are, through their use in numerous conventional and sustainable applications, very important to our daily lives, including to foster the necessary transition to a more circular society. The characterization of zeolite-based materials has a tremendous history and a great number of applications and properties of these materials have been discovered in the past decades. This review focuses on recently developed novel as well as more conventional techniques applied with the aim of better understanding zeolite-based materials. Recently explored analytical methods, e.g. atom probe tomography, scanning transmission X-ray microscopy, confocal fluorescence microscopy and photo-induced force microscopy, are discussed on their important contributions to the better understanding of zeolites as they mainly focus on the micro- to nanoscale chemical imaging and the revelation of structure-composition-performance relationships. Some other techniques have a long and established history, e.g. nuclear magnetic resonance, infrared, neutron scattering, electron microscopy and X-ray diffraction techniques, and have gone through increasing developments allowing the techniques to discover new and important features in zeolite-based materials. Additional to the increasing application of these methods, multiple techniques are nowadays used to study zeolites under working conditions (i.e. the in situ/operando mode of analysis) providing new insights in reaction and deactivation mechanisms

The active phase in cobalt-based Fischer-Tropsch synthesis

Fischer-Tropsch synthesis (FTS) is an industrial catalytic process that converts a mixture of CO and hydrogen into long-chain hydrocarbons. These products are used as clean transportation fuels and chemical building blocks. The solid catalysts used in the process are complex multi-component systems. Therefore, unambiguously determining the catalytically active phase under reaction conditions remains challenging and thus a topic of debate. The active phase in cobalt-based FTS, including the reaction pathways it catalyzes, has been of industrial and academic interest for many years. It provides direct ways to control the output of the process. The delineation between an active and inactive phase is often unclear, as different phases (i.e., cobalt oxide, carbide, and metal) have different catalytic behavior. This review focuses on cobalt-based FTS materials, with a special focus on the industrially applied cobalt/TiO2 system. The various cobalt phases are reviewed and discussed with respect to the most recent literature

Дисульфідні зв’язки у структурно-функціональній організації протеїнів

Обговорюються сучасні уявлення про роль дисульфідного зв’язку в забезпеченні структурно-функціональних властивостей протеїнів плазми крові. Узагальнюються нові підходи до можливостей рефолдингу рекомбінантних і секреторних протеїнів. Розглянуто проблему окисного фолдингу та значення дисульфідного зв’язку для посттрансляційного «дозрівання» секреторних протеїнів у порожнині ендоплазматичного ретикулума з участю редуктазної системи ензимів.Обсуждаются современные представления о роли дисульфидной связи в обеспечении структурно-функциональних свойств протеинов плазмы крови. Обобщаются новые подходы к возможностям рефолдинга рекомбинантных и секреторных протеинов. Рассмотрены проблема окислительного фолдинга и значение дисульфидной связи для посттрансляционного «созревания» секреторных протеинов в эндоплазматическом ретикулуме с участием редуктазной системы энзимов.Modern vision about disulfide bonds role in light of providing the structural and functional properties of blood plasma proteins is proposed. New approaches concerning recombinant and secretory proteins refolding are generalized. A problem concerning oxidative folding and disulfide bonds significance for secretory protein posttranslation ripening inside of endoplasmic reticulum with reductase enzyme system participation is discussed

Carbon Deposit Analysis in Catalyst Deactivation, Regeneration, and Rejuvenation

Hydrocarbon conversion catalysts suffer from deactivation by deposition or formation of carbon deposits. Carbon deposit formation is thermodynamically favored above 350 °C, even in some hydrogen-rich environments. We discuss four basic mechanisms: a carbenium-ion based mechanism taking place on acid sites of zeolites or bifunctional catalysts, a metal-induced formation of soft coke (i.e., oligomers of small olefins) on bifunctional catalysts, a radical-mediated mechanism in higher-temperature processes, and fast-growing carbon filament formation. Catalysts deactivate because carbon deposits block pores at different length scales, or directly block active sites. Some deactivated catalysts can be re-used, others can be regenerated or have to be discarded. Catalyst and process design can mitigate the effects of deactivation. New analytical tools allow for the direct observation (in some cases even under in situ or operando conditions) of the 3D-distribution of coke-type species as a function of catalyst structure and lifetime

Visualizing the Structure, Composition and Activity of Single Catalyst Particles for Olefin Polymerization and Polyolefin Decomposition

The structural and morphological characterization of individual catalyst particles for olefin polymerization, as well as for the reverse process of polyolefin decomposition, can provide an improved understanding for how these catalyst materials operate under relevant reaction conditions. In this review, we discuss an emerging analytical toolbox of 2D and 3D chemical imaging techniques that is suitable for investigating the chemistry and reactivity of related catalyst systems. While synchrotron-based X-ray microscopy still provides unparalleled spatial resolutions in 2D and 3D, a number of laboratory-based techniques, most notably focused ion beam-scanning electron microscopy, confocal fluorescence microscopy, infrared photoinduced force microscopy and laboratory-based X-ray nano-computed tomography, have helped to significantly expand the arsenal of analytical tools available to scientists in heterogeneous catalysis and polymer science. In terms of future research, the review outlines the role and impact of in situ and operando (spectro−)microscopy experiments, involving sophisticated reactors as well as online reactant and product analysis, to obtain real-time information on the formation, decomposition, and mobility of polymer phases within single catalyst particles. Furthermore, the potential of fluorescence microscopy, X-ray microscopy and optical microscopy is highlighted for the high-throughput characterization of olefin polymerization and polyolefin decomposition catalysts. By combining these chemical imaging techniques with, for example, chemical staining methodologies, selective probe molecules as well as particle sorting approaches, representative structure–activity relationships can be derived at the level of single catalyst particles