Video Experimental Relacionado

Updated: Oct 10, 2025

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Published on: April 10, 2018

La evolución fotoquímica de los hidratos de bis (difosfina) níquel permite la electrocatálisis de bajo sobrepotencial

Bethany M Stratakes¹, Kaylee A Wells², Daniel A Kurtz¹

¹Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.

Journal of the American Chemical Society

|December 8, 2021

Resumen

Los investigadores desarrollaron fotoelectrocatalizadores de níquel para la evolución eficiente del hidrógeno (H2) utilizando luz visible. Este avance permite la generación de combustible solar sin altos potenciales o materiales semiconductores.

Área de la Ciencia:

La fotoquímica
Catálisis
Ciencias de los materiales

Sus antecedentes:

Se buscan complejos de metales de transición de primera fila para aplicaciones de combustible solar.
Los catalizadores eficientes de recolección de luz y formación de enlaces son cruciales para la generación de combustible solar.

Objetivo del estudio:

Para reportar nuevos fotoelectrocatalizadores de níquel para la evolución del hidrógeno.
Para aclarar el mecanismo de la evolución de H2 impulsado por la luz visible.

Principales métodos:

Se utilizan complejos de hidróxido de níquel bis (difosfina).
Utilizó espectroscopia de resolución temporal y mediciones de rendimiento cuántico.
Se han realizado análisis termodinámicos.

Principales resultados:

Evolución de H2 impulsada por la luz visible mediante el uso de complejos de níquel.
Propuso un mecanismo que involucra la homólisis del enlace Ni-H desde un estado excitado singlet.
Se logró una mejora de más de 500 mV en el sobrepotencial electroquímico bajo iluminación, lo que permite la evolución de H2 a 0 mV de sobrepotencial.

Conclusiones:

Los complejos de níquel pueden funcionar como fotoelectrocatalizadores eficientes para la evolución de H2.
La comprensión de la fotoquímica del hidruro de metal de transición de primera fila es clave para el diseño del catalizador.
Este sistema ofrece una vía para la generación de combustible solar sin agentes de sacrificio o semiconductores.

Más Videos Relacionados

Simple Methods for the Preparation of Non-noble Metal Bulk-electrodes for Electrocatalytic Applications

Simple Methods for the Preparation of Non-noble Metal Bulk-electrodes for Electrocatalytic Applications

Published on: June 21, 2017

Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase

Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase

Published on: December 4, 2017

Videos de Conceptos Relacionados

Catalysis

Catalysis

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.

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

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...

Reduction of Alkenes: Catalytic Hydrogenation

Reduction of Alkenes: Catalytic Hydrogenation

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...

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

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.

Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation

Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation

Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...

Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride

Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride

Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...