Video Experimental Relacionado
Updated: Jan 2, 2026
10:57
Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
18.9K
Ajuste del entorno de coordinación en catalizadores monoatómicos para lograr reacciones de reducción de oxígeno
Jinqiang Zhang1, Yufei Zhao1, Chen Chen2
1Center for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science , University of Technology Sydney , Ultimo , New South Wales 2007 , Australia.
Journal of the American Chemical Society
|December 6, 2019
Resumen
Desarrollamos catalizadores de un solo átomo de metal en carbono codificado N, S para reacciones eficientes de reducción de oxígeno (ORR). Los catalizadores centrados en el hierro (Fe-SAs / NSC) mostraron un rendimiento y una estabilidad superiores en comparación con el cobalto y el níquel, superando al platino / carbono comercial.
Área de la Ciencia:
- Ciencias de los materiales
- La electroquímica
- Catálisis
Sus antecedentes:
- Los catalizadores metálicos dispersos atómicamente son cruciales para la conversión eficiente de energía a través de la reacción de reducción de oxígeno (ORR).
- El desarrollo de catalizadores ORR altamente activos y estables es esencial para el avance de la tecnología de pilas de combustible.
Objetivo del estudio:
- Para sintetizar e investigar átomos de metal únicos anclados en el carbono poroso N,S-codificado (NSC) para ORR.
- Para explorar la correlación estructura-rendimiento de los catalizadores de un solo átomo de Fe, Co y Ni (SAC) en NSC.
- Comprender la influencia de la coordinación metal-ligando en la actividad catalítica.
Principales métodos:
- Síntesis asistida por plantilla de la matriz de carbono codificada N,S.
- Anclaje de átomos individuales de Fe, Co y Ni en la matriz NSC.
- Caracterización estructural mediante técnicas analíticas avanzadas.
- Evaluación electroquímica de la actividad y estabilidad de la ORR.
- Cálculos de la teoría funcional de la densidad (DFT) para aclarar los mecanismos de reacción.
Principales resultados:
- Se observaron entornos de coordinación distintos: Fe-SAs/NSC presentaba sitios FeN4S2, mientras que Co-SAs/NSC y Ni-SAs/NSC exhibieron enlaces M-S que formaban sitios M N3S1.
- Los cálculos de DFT predijeron una mayor actividad para FeN4S2 debido a propiedades electrónicas favorables y barreras de energía más bajas.
- Fe-SAs/NSC demostró un rendimiento ORR superior, superior al Pt/C comercial, con una excelente tolerancia al metanol y una estabilidad a largo plazo (5000 ciclos).
Conclusiones:
- La estructura de coordinación de los átomos de un solo metal tiene un impacto significativo en la actividad catalítica de ORR.
- El Fe-SAs/NSC representa un catalizador ORR altamente eficiente y estable, que ofrece una alternativa prometedora a los catalizadores basados en platino.
- Este estudio proporciona información crítica para el diseño racional de catalizadores de un solo átomo con propiedades sintonizables para aplicaciones energéticas.
Videos de Conceptos Relacionados
01:13Introduction to Mechanisms of Enzyme Catalysis
10.3K
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes...
10.3K
02:50Catalysis
30.0K
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.
30.0K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.8K
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...
3.8K
01:22Factors Influencing the Rate of Chemical Reactions
7.7K
A variety of factors influence the rate of chemical reactions. For a chemical reaction to happen, atoms must collide with enough energy to overcome the repulsion between their electrons. This energy is called activation energy. Factors influencing the rate of reaction either lower the activation energy or increase the likelihood of a successful collision.
Concentration and Pressure:
The more particles present within a given space, the more likely those particles are to bump into one another....
Concentration and Pressure:
The more particles present within a given space, the more likely those particles are to bump into one another....
7.7K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
12.4K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
12.4K
02:13Reduction of Alkenes: Catalytic Hydrogenation
13.8K
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...
13.8K