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921.
For over 20 years, researchers have agreed that when pentacesium trihydrogen tetrasulfate hydrate (Cs5H3(SO4)4·xH2O) is heated through 141 °C, the observed conductivity increase corresponds to a physical transformation: a first-order superprotonic phase transition. A careful high-temperature phase behavior examination of this acid salt was performed by means of simultaneous thermogravimetric and differential scanning calorimetry, conventional and modulated differential scanning calorimetry, and impedance spectroscopy. The results present evidence that this transformation is of chemical, instead of physical nature. The conductivity increase is an exclusive consequence of a partial thermal decomposition, where liquid water (dissolving part of the surface salt) and hygroscopic cesium pyrosulfate (Cs2S2O7), as decomposition products, behave like a polymer electrolyte membrane where the proton transport mechanism includes the vehicle type, using hydronium (H3O+) as a charge carrier. Additionally, it was found that the intermediate temperature transformation (so-called isostructural phase transition) at around 87 °C is also of chemical nature. 相似文献
922.
Ruthenium-catalyzed hydrogen auto-transfer reactions for the direct enantioselective conversion of lower alcohols to higher alcohols are surveyed. These processes enable completely atom-efficient carbonyl addition from alcohol proelectrophiles in the absence of premetalated reagents or metallic reductants. Applications in target-oriented synthesis are highlighted, and a brief historical perspective on ruthenium-catalyzed hydrogen transfer processes is given.Ruthenium-catalyzed hydrogen auto-transfer reactions for the direct enantioselective conversion of lower alcohols to higher alcohols are surveyed. A brief historical perspective on ruthenium-catalyzed hydrogen transfer is given. 相似文献
923.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
924.
925.
Louis Godeffroy Dr. Paolo Ciocci Dr. Nathaly Ortiz Peña Dr. Damien Alloyeau Dr. Jean-Marc Noël Dr. Jean-François Lemineur Dr. Frédéric Kanoufi 《Angewandte Chemie (International ed. in English)》2023,62(29):e202304950
This work proposes a novel method for measuring the intrinsic activity of single metal-based nanoparticles towards water reduction in neutral media at industrially relevant current densities. Instead of using gas nanobubbles as proxy, the method uses optical microscopy to track the local footprint of the reaction through the precipitation of metal hydroxide, which is associated to the local pH increase during electrocatalysis. The results show the electrocatalytic activities of different types of metal nanoparticles and bifunctionnal core-shell nanostructures made of Ni and Pt, and demonstrate the importance of metal hydroxide nano-shells in enhancing electrocatalysis. This method should be generalizable to any electrocatalytic reaction involving pH changes such as nitrate or CO2 reduction. 相似文献
926.
927.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献