Video Experimental Relacionado

Updated: Feb 20, 2026

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes

Published on: June 24, 2022

Activación de hidrógeno mediante formación de dihidruro en un catalizador de átomo único Rh1/Fe3O4(001)

Chunlei Wang¹, Panukorn Sombut¹, Lena Puntscher¹

¹Institute of Applied Physics, TU Wien, Vienna, Austria.

Angewandte Chemie (International ed. in English)

|February 19, 2026

Resumen

Átomos aislados de rodio en óxido de hierro activan el hidrógeno a través de un intermedio de dihidruro, imitando catalizadores homogéneos y uniendo los mecanismos de catálisis homogénea y heterogénea sin desbordamiento de hidrógeno.

Área de la Ciencia:

Catálisis heterogénea
Ciencia de superficies
Catálisis de átomo único

Sus antecedentes:

La activación del hidrógeno es crucial para las reacciones de hidrogenación.
La catálisis heterogénea típicamente implica adsorción disociativa en nanopartículas metálicas.
Los catalizadores homogéneos activan el H2 a través de intermedios de dihidruro o dihidrógeno en un centro metálico único.

Objetivo del estudio:

Investigar la activación de hidrógeno por adátomos aislados de Rh en Fe3O4(001).
Elucidar el mecanismo de activación de hidrógeno a nivel de átomo único.
Establecer un vínculo mecanicista entre la catálisis homogénea y heterogénea.

Principales métodos:

Desorción programada de temperatura (TPD)
Espectroscopía de fotoelectrones emitidos por rayos X (XPS)
Microscopía de túnel de barrido (STM)
Experimentos de intercambio isotópico
Cálculos de teoría de funcionales de densidad (DFT)
Cálculos de aproximación de fase aleatoria (RPA)

Principales resultados:

Los adátomos aislados de Rh en Fe3O4(001) activan el hidrógeno, formando especies estables de dihidruro.
La adsorción de hidrógeno es fuerte (≈1 eV) y localizada exclusivamente en sitios de Rh aislados.
No se observó desbordamiento de hidrógeno atómico.
Los cálculos de DFT y RPA confirmaron una conversión sin barreras al dihidruro y su estabilidad.

Conclusiones:

Los átomos de Rh únicos escinden el hidrógeno a través de una vía de dihidruro, similar a los catalizadores homogéneos.
Este estudio establece un puente mecanicista entre la catálisis homogénea y heterogénea.
Los átomos únicos aislados pueden exhibir una reactividad única distinta de las nanopartículas.

Palabras clave:

teoría de funcionales de densidad adsorción de hidrógeno superficies de óxido metálico microscopía de túnel de barrido catálisis de átomo único

Más Videos Relacionados

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions

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

Videos de Conceptos Relacionados

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 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 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.

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.

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 reactions,...

Radical Anti-Markovnikov Addition to Alkenes: Mechanism

Radical Anti-Markovnikov Addition to Alkenes: Mechanism

The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...