Video Experimental Relacionado
Updated: May 22, 2025
08:46
Methane Hydrate Crystallization on Sessile Water Droplets
Published on: May 26, 2021
2.3K
El agrupamiento de agua modula la actividad y permite la formación de productos hidrogenados durante la
Hannah Fejzić1, Ritesh Kumar1, Reginaldo J Gomes1
1Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States.
Journal of the American Chemical Society
|May 19, 2025
Resumen
El control de la forma del agua en disolventes no acuosos durante la reacción de reducción de monóxido de carbono (CORR) aumenta el rendimiento del producto. Los grupos de agua microheterogéneos mejoran la CORR al metano y al etileno, a diferencia de los sistemas microhomogéneos que favorecen la reacción de evolución del hidrógeno (HER).
Área de la Ciencia:
- La electroquímica
- Química Física
- Ciencias de los materiales
Sus antecedentes:
- El papel del agua en las reacciones electroquímicas es complejo, a menudo actúa como solvente y fuente de protones.
- Comprender la actividad específica del agua es crucial para optimizar las transformaciones electroquímicas.
Objetivo del estudio:
- Para controlar experimentalmente la especiación del agua y la actividad en disolventes aproticos durante la reacción de reducción del monóxido de carbono (CORR).
- Investigar el impacto de diferentes entornos acuáticos (microheterogéneos frente a microhomogéneos) en la selectividad del producto CORR.
Principales métodos:
- Utilizando medios de disolvente apróticos para controlar la especiación y la actividad del agua.
- Realización de la reacción de reducción de monóxido de carbono (CORR) bajo diferentes concentraciones de agua y entornos de disolventes.
- Analizar los productos de reacción, incluidos el metano, el etileno y el hidrógeno, para determinar la eficiencia de Faradaic.
Principales resultados:
- Los disolventes apróticos que soportan los grupos de agua microheterogéneos aumentaron significativamente los productos CORR, obteniendo hasta un 22% de eficiencia de etileno Faradaic en acetonitrilo.
- Los sistemas microhomogéneos, donde el agua está integrada en la red de disolventes, resultaron principalmente en la reacción de evolución del hidrógeno (HER).
- La actividad del agua se correlaciona directamente con la selectividad entre CORR y HER.
Conclusiones:
- La especiación y la actividad del agua son parámetros críticos y ajustables en la electroquímica no acuosa.
- El diseño de electrolitos con microambientes de agua controlados puede dirigir las reacciones electroquímicas hacia los productos deseados.
- Los hallazgos ofrecen ideas para optimizar la reacción de reducción de CO2 (CO2RR) y HER mediante el control de la actividad del agua.
Videos de Conceptos Relacionados
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.2K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.2K
02:13Reduction of Alkenes: Catalytic Hydrogenation
11.8K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
11.8K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
13.8K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
13.8K
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
8.3K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
8.3K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
7.6K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
7.6K
01:20Aldehydes and Ketones with Water: Hydrate Formation
3.0K
An oxygen-based nucleophile, like water, can undergo addition reactions with aldehydes and ketones. The reaction leads to the formation of hydrates, also referred to as 1,1-diols or geminal diols.
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
3.0K