Video Experimental Relacionado
Updated: Jul 4, 2025
06:32
A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
19.6K
Aliviar el bloqueo de OH en la superficie del catalizador por el efecto de punción de los sitios de un solo átomo
Xingen Lin1, Wenfeng Hu2, Jie Xu3
1Department of Endocrinology, Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China.
Journal of the American Chemical Society
|February 7, 2024
Resumen
Los catalizadores monoatómicos evitan efectivamente el bloqueo del sitio activo en la electrólisis del agua alcalina. Este avance mejora el rendimiento y la estabilidad de la reacción de evolución del hidrógeno para aplicaciones industriales.
Área de la Ciencia:
- Ciencias de los materiales
- La electroquímica
- Catálisis
Sus antecedentes:
- Los catalizadores de metales de transición no preciosos se prefieren para la electrólisis industrial del agua alcalina debido a su costo.
- La unión excesiva de hidroxilo (OH) a los sitios activos dificulta el rendimiento catalítico, especialmente en las reacciones de evolución de hidrógeno (HER).
Objetivo del estudio:
- Investigar la eficacia de los sitios de un solo átomo para aliviar el bloqueo de OH para mejorar la HER alcalina.
- Desarrollar electrocatalizadores altamente activos y estables para la electrólisis del agua alcalina a escala industrial.
Principales métodos:
- "Capacidad" igual o superior a 200 W; o
- Pruebas de rendimiento electroquímico, incluidas las mediciones de sobrepotencial y actividad de masa.
- Los cálculos de la Teoría Funcional de Densidad (DFT) para aclarar el mecanismo.
Principales resultados:
- Los átomos de Ru individuales en el carburo de tungsteno redujeron significativamente el sobrepotencial en más de 130 mV.
- Logró un aumento de 16 veces en la actividad de masa en comparación con el platino comercial en carbono (Pt/C).
- Potencial celular demostrado ultrabajo (1,79 V) y alta estabilidad a 1,0 A·cm-2 en electrolizadores de agua de membrana de intercambio de aniones.
Conclusiones:
- Los sitios de un solo átomo exhiben un "efecto de punción" para superar el bloqueo de OH, aumentando la HER alcalina.
- El catalizador desarrollado es prometedor para una eficiente y estable electrólisis industrial del agua alcalina.
- Los hallazgos se pueden generalizar a otros catalizadores de metales de transición, avanzando en la tecnología de electrólisis.
Más Videos Relacionados
Videos de Conceptos Relacionados
02:50Catalysis
26.9K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
26.9K
01:13Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
2.9K
Hydrolysis of esters under acidic conditions proceeds through a nucleophilic acyl substitution. In the presence of excess water, the reaction proceeds in a reversible manner, forming carboxylic acids and alcohols.
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
2.9K
01:29Leveling Effect
806
In acid-base chemistry, the leveling effect refers to the limitation imposed by the solvent on the strength of acids and bases in solution. When a base stronger than the solvent's conjugate base is used, it deprotonates the solvent until the base is entirely consumed, making it ineffective against weaker acids. Conversely, an acid stronger than the solvent's conjugate acid protonates the solvent until the acid is depleted, rendering it ineffective against weaker bases. Essentially, the...
806
02:13Reduction of Alkenes: Catalytic Hydrogenation
12.0K
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...
12.0K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
7.7K
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.
7.7K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.3K
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...
3.3K