Defining active catalyst structure and reaction pathways from ab initio molecular dynamics and operando XAFS

Dehydrogenation of dimethylaminoborane by rhodium clusters

Roger Rousseau, Gregory K. Schenter, John L. Fulton, John Linehan, Mark H. Engelhard, Thomas Autrey

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

We present the results of a detailed operando XAFS and density functional theory (DFT)-based ab initio molecular dynamics (AIMD) investigation of a proposed mechanism of the dehydrogenation of dimethylaminoborane (DMAB) by a homogeneous Rh4 cluster catalyst. Our AIMD simulations reveal that previously proposed Rh structures, based on XAFS measurements, are highly fluxional, exhibiting both metal cluster and ligand isomerizations and dissociation that can only be accounted for by examining a finite temperature ensemble. It is found that a fluxional species Rh4(H2BNMe 2)8 2+ is fully compatible with operando XAFS measurements, suggesting that this species may be the observed catalyst resting state. On the basis of this assignment, we propose a mechanism for catalytic DMAB dehydrogenation that exhibits an energy barrier of approximately 28 kcal/mol.

Original languageEnglish
Pages (from-to)10516-10524
Number of pages9
JournalJournal of the American Chemical Society
Volume131
Issue number30
DOIs
Publication statusPublished - Aug 5 2009

Fingerprint

Rhodium
Dehydrogenation
Molecular Dynamics Simulation
Molecular dynamics
Catalysts
Energy barriers
Isomerization
Density functional theory
Metals
Ligands
Temperature
Computer simulation

ASJC Scopus subject areas

  • Chemistry(all)
  • Catalysis
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Defining active catalyst structure and reaction pathways from ab initio molecular dynamics and operando XAFS : Dehydrogenation of dimethylaminoborane by rhodium clusters. / Rousseau, Roger; Schenter, Gregory K.; Fulton, John L.; Linehan, John; Engelhard, Mark H.; Autrey, Thomas.

In: Journal of the American Chemical Society, Vol. 131, No. 30, 05.08.2009, p. 10516-10524.

Research output: Contribution to journalArticle

@article{b7e603d00f464e26bedfb10855623960,
title = "Defining active catalyst structure and reaction pathways from ab initio molecular dynamics and operando XAFS: Dehydrogenation of dimethylaminoborane by rhodium clusters",
abstract = "We present the results of a detailed operando XAFS and density functional theory (DFT)-based ab initio molecular dynamics (AIMD) investigation of a proposed mechanism of the dehydrogenation of dimethylaminoborane (DMAB) by a homogeneous Rh4 cluster catalyst. Our AIMD simulations reveal that previously proposed Rh structures, based on XAFS measurements, are highly fluxional, exhibiting both metal cluster and ligand isomerizations and dissociation that can only be accounted for by examining a finite temperature ensemble. It is found that a fluxional species Rh4(H2BNMe 2)8 2+ is fully compatible with operando XAFS measurements, suggesting that this species may be the observed catalyst resting state. On the basis of this assignment, we propose a mechanism for catalytic DMAB dehydrogenation that exhibits an energy barrier of approximately 28 kcal/mol.",
author = "Roger Rousseau and Schenter, {Gregory K.} and Fulton, {John L.} and John Linehan and Engelhard, {Mark H.} and Thomas Autrey",
year = "2009",
month = "8",
day = "5",
doi = "10.1021/ja901480u",
language = "English",
volume = "131",
pages = "10516--10524",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "30",

}

TY - JOUR

T1 - Defining active catalyst structure and reaction pathways from ab initio molecular dynamics and operando XAFS

T2 - Dehydrogenation of dimethylaminoborane by rhodium clusters

AU - Rousseau, Roger

AU - Schenter, Gregory K.

AU - Fulton, John L.

AU - Linehan, John

AU - Engelhard, Mark H.

AU - Autrey, Thomas

PY - 2009/8/5

Y1 - 2009/8/5

N2 - We present the results of a detailed operando XAFS and density functional theory (DFT)-based ab initio molecular dynamics (AIMD) investigation of a proposed mechanism of the dehydrogenation of dimethylaminoborane (DMAB) by a homogeneous Rh4 cluster catalyst. Our AIMD simulations reveal that previously proposed Rh structures, based on XAFS measurements, are highly fluxional, exhibiting both metal cluster and ligand isomerizations and dissociation that can only be accounted for by examining a finite temperature ensemble. It is found that a fluxional species Rh4(H2BNMe 2)8 2+ is fully compatible with operando XAFS measurements, suggesting that this species may be the observed catalyst resting state. On the basis of this assignment, we propose a mechanism for catalytic DMAB dehydrogenation that exhibits an energy barrier of approximately 28 kcal/mol.

AB - We present the results of a detailed operando XAFS and density functional theory (DFT)-based ab initio molecular dynamics (AIMD) investigation of a proposed mechanism of the dehydrogenation of dimethylaminoborane (DMAB) by a homogeneous Rh4 cluster catalyst. Our AIMD simulations reveal that previously proposed Rh structures, based on XAFS measurements, are highly fluxional, exhibiting both metal cluster and ligand isomerizations and dissociation that can only be accounted for by examining a finite temperature ensemble. It is found that a fluxional species Rh4(H2BNMe 2)8 2+ is fully compatible with operando XAFS measurements, suggesting that this species may be the observed catalyst resting state. On the basis of this assignment, we propose a mechanism for catalytic DMAB dehydrogenation that exhibits an energy barrier of approximately 28 kcal/mol.

UR - http://www.scopus.com/inward/record.url?scp=68049113667&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=68049113667&partnerID=8YFLogxK

U2 - 10.1021/ja901480u

DO - 10.1021/ja901480u

M3 - Article

VL - 131

SP - 10516

EP - 10524

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 30

ER -