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The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate. To understand the impact of entropy, we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures. AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased. Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction. The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3dorbital energy levels. We provided explanations consistent with the principles of thermodynamics and statistical physics. The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.

Fe-S-1 zeolite with +2 valence framework-Fe exhibits a higher reactivity than that with +3 valence state to catalyze ethane dehydrogenation because of the coordinate structure, electronic property, and spin state.

Designing high-performance hydrogen evolution reaction (HER) catalysts is crucial for seawater splitting. Herein, we demonstrate a facile Anderson-type polyoxometalate-assisted synthesis route to prepare defect-rich doped 1T/2H-MoSe2nanosheets. As demonstrated, the optimized defect-rich doped 1T/2H-MoSe2nanosheets display low overpotentials of 116 and 274 mV to gain 10 mA cm–2in acidic and simulated seawater for the HER, respectively. A magnesium (Mg)/seawater battery was fabricated with the defect-rich doped 1T/2H-MoSe2nanosheet cathode, displaying the highest power density of up to 7.69 mW cm–2and stable galvanostatic discharging over 24 h. The theoretical and experimental investigations show that the superior HER and battery performances of the heteroatom-doped MoSe2nanosheets are attributed to both the improved intrinsic catalytic activity (effective activation of water and favorable subsequent hydrogen desorption) and the abundant active sites, benefiting from the favorable catalytic factors of the doped heteroatom, 1T phase, and defects. Our work presents an intriguing structural modulation strategy to design high-performance catalysts toward both HER and Mg/seawater batteries.

First-principles calculations have revealed that the interfacial structure between two components has an important influence on the mechanism of photocatalytic overall water splitting of Ta3N5single crystals grown in the surface of KTaO3.

CO2oxidative propane dehydrogenation to propylene (CO2-ODH) is promising for propylene production and CO2utilization. Developing an efficient bifunctional CO2-ODH site capable of activating C–H and C=O bonds with inhibited C–C scission capacity remains a challenge. This work describes a La-modified binuclear Feoxo(La-Feoxo) site stabilized on a silicalite-1 support; it achieves 32.7% propane conversion (1.72 times higher than the direct propane dehydrogenation [PDH] counterpart) with 83.2% propylene selectivity. The promising CO2-ODH performance, attributed to the appropriate FeOxdispersion and La modification, balances the acid-base property, which helps stabilize key HCOO∗ intermediates toward enhanced CO2-assisted H removal efficiency. The inferior CO2-ODH performance of isolated Feisoand clustered Fe4O6was rationalized by insufficient CO2activation and huge dry reforming contribution, respectively. We propose H2dissociative binding energy and O∗ binding energy as descriptors for the acid-base strength and catalytic CO2dissociation capacity in that they predict the CO2-ODH and extent of propane dry reforming.