Heterogeneous acid and base catalysts play a crucial role in many important chemical processes. Hard Lewis and Brønsted acid catalysts like silica-alumina and zeolites have been widely applied in numerous reactions; however, developing reusable and active soft Lewis acid catalysts remain a challenge. Herein, we demonstrate for the rst time that a highly dispersed supported platinum catalyst can act as a heterogeneous soft Lewis acid. High turnover numbers and reusability were observed in the isomerization of allylic esters under solvent-free conditions. Moreover, the as-prepared catalysts are characterized by Xray photoelectron spectroscopy (XPS) and X-ray absorption ne structure (XAFS) analyses, revealing that the highly dispersed Pt clusters with Pt-Cl bonds play a key role in the high activity. The residual chloride anion enhances the Lewis acidity of the Pt metal center and thus improves the catalytic activity. Simultaneously, the high catalytic activity of Pt/CeO 2 with residual chloride and the soft Lewis acid mechanism are also proved by density functional theory (DFT) calculations based on the model reaction.

Heterogeneous acid and base catalysts play a crucial role in many important chemical processes. Hard Lewis and Brønsted acid catalysts like silica-alumina and zeolites have been widely applied in numerous reactions; however, developing reusable and active soft Lewis acid catalysts remain a challenge. Herein, we demonstrate for the first time that a highly dispersed supported platinum catalyst can act as a heterogeneous soft Lewis acid. High turnover numbers and reusability were observed in the isomerization of allylic esters under solvent-free conditions. Moreover, the as-prepared catalysts are characterized by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) analyses, revealing that the highly dispersed Pt clusters with Pt–Cl bonds play a key role in the high activity. The residual chloride anion enhances the Lewis acidity of the Pt metal center and thus improves the catalytic activity. Simultaneously, the high catalytic activity of Pt/CeO2 with residual chloride and the soft Lewis acid mechanism are also proved by density functional theory (DFT) calculations based on the model reaction.

For extending the lifetime and improving the safety of lithium-ion batteries, the decomposition mechanism of electrolytes in lithium-ion batteries was kinetically and stereospecifically investigated in simplified reaction systems, which were in contact with the charged positive electrodes including Li1−xCoO2 as an active material removed from batteries. By identifying the products, mainly vinylene carbonate (VC) was detected by gas chromatography as an oxidation product of ethylene carbonate (EC). The kinetic isotope effects of the reaction were examined using EC and deuterium-labeled EC-D4. The kH/kD was found to be 2.9 suggesting the C–H bond cleavage step was irreversible and corresponds to the rate-determining step of the overall process in the reaction. Moreover, Arrhenius and Eyring plots and stereospecific studies using syn-substituted EC-D2 indicated that the transition state has a rigid structure and that the elimination of hydrogens from EC proceeds mainly via syn stereochemistry. Upon a change in the charge potential of Li1−xCoO2 from 4.5 V to 4.1 V, the rate of formation of VC decreased. PF6−, PO3F2−, and PO2F2− relating to LiPF6 promoted the generation of VC.