Catalysis

Computational Study of Ni-Catalyzed C−H Functionalization: Factors That Control the Competition of Oxidative Addition and Radical Pathways

  • By Aude Marjolin
  • 2 August 2017

To guide the development of a more diverse set of Ni-catalyzed C−H bond functionalizations, a thorough understanding of the mechanisms, reactivity, and selectivity of these reactions is required. Peng Liu and his student Humair Omer have undertaken a computational study of the functionalization of the C−H bonds in molecules that contain the N,N-bidentate directing group with Ni catalyst and various coupling  partners, e.g. phenyl iodide (Ph−I), which has been published in the July 26, 2017 issue of the Journal of the American Chemical Society.

Giannis Mpourmpakis Lands Cover of Catalysis Science & Technology

  • By Aude Marjolin
  • 31 May 2017

Research from Giannis Mpourmpakis' group was recently featured on the inside front cover of the Royal Society of Chemistry journal, Catalysis Science & Technology. The team’s investigations into a more energy-efficient catalytic process to produce olefins--the building blocks for polymer production--could impact potential applications in diverse technology areas from green energy and sustainable chemistry to materials engineering and catalysis. 
 

Structure-Activity Relations in Heterogeneous Catalysis – A View from Computational Chemistry

Speaker(s): 
Phillipe Sautet
Dates: 
Friday, March 17, 2017 - 9:30am to 10:30am

The understanding of the catalytic properties of nanoparticle catalysts and the design of optimal composition and structures demands fast methods for the calculation of adsorption energies. By exploring the adsorption of O and OR (R=OH, OOH, OCH3) adsorbates on a large range of surface sites with 9 transition metals, we propose new structure sensitive scaling relations between the adsorption energy of two adsorbates that are valid for all metals and for all surface sites.1 This opens the way for a new class of activity volcano plots where the descriptor is not an energy...

In Silico Searches for Efficient Renewable Energy Catalysts Through Chemical Compound Space

Speaker(s): 
John Keith
Dates: 
Friday, February 3, 2017 - 11:30am to 12:30pm

This talk will provide an overview of our group’s work using both standard and atypical high-performance computational chemistry modeling to elucidate atomic scale reaction mechanisms of catalytic reactions. I will introduce our toolkit of in silico methods for accurately modeling solvating environments and realistic nanoscale architectures. I will then present how these methods can be used for predictive insights into chemical and material design. The talk will then summarize our progress in unraveling reaction mechanisms for 1) electrochemical CO2 reduction with...

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Personal | Department
Department of Chemical and Petroleum Engineering, University of Pittsburgh
Ph.D., Theoretical and Computational Chemistry, University of Crete, 2006
Summary:

My research expertise is interdisciplinary, blending concepts and techniques from Chemistry, Physics, Materials Science and Chemical Engineering. I use theory and computation to investigate the physicochemical properties of nanomaterials with potential applications in diverse nanotechnological areas, ranging from energy generation and storage, to materials design, nanoparticle growth, magnetism, and catalysis.

In the Computer-Aided Nano and Energy Lab (C.A.N.E.LA.), led by Prof. Mpourmpakis, we use theory and computation to investigate the physicochemical properties of nanomaterials with potential applications in diverse nanotechnological areas, ranging from green energy generation and storage to materials engineering and catalysis. Our laboratory core expertise lies on "ab-initio" electronic-structure theoretical calculations. We develop structure-activity relationships and apply multiscale tools to elucidate complex chemical processes that take place on nanomaterials. Ultimately, we design novel nanostructures with increased, molecular-level precision and tailored multifunctionality. 

Most Cited Publications: 
  1. "SiC Nanotubes:  A Novel Material for Hydrogen Storage," Giannis Mpourmpakis and George E. Froudakis, George P. Lithoxoos and Jannis Samios, Nano Lett. 6, 1581 (2006)
  2. "Carbon Nanoscrolls:  A Promising Material for Hydrogen Storage," Giannis Mpourmpakis, Emmanuel Tylianakis, and George E. Froudakis, Nano Lett. 7, 1893 (2007)
  3. "Correlating Particle Size and Shape of Supported Ru/γ-Al2O3 Catalysts with NH3 Decomposition Activity," Ayman M. Karim, Vinay Prasad, Giannis Mpourmpakis, William W. Lonergan, Anatoly I. Frenkel, Jingguang G. Chen and Dionisios G. Vlachos, J. Am. Chem. Soc.131, 12230 (2009)
  4. "Why boron nitride nanotubes are preferable to carbon nanotubes for hydrogen storage?: An ab initio theoretical study," Giannis Mpourmpakis, George E. Froudakis, Catalysis Today 120, 341 (2007)
  5. "Stabilization of Si-based cage clusters and nanotubes by encapsulation of transition metal atoms," Antonis N Andriotis, Giannis Mpourmpakis, George E Froudakis2 and Madhu Menon, New J. Phys. 4, 78 (2002)
Recent Publications: 
  1. "Site-selective Substitution of Gold Atoms in the Au24(SR)20Nanocluster by Silver," Qi Li, Michael G. TaylorKristin Kirschbaum, Kelly J. LambrightXiaofan ZhuGiannis MpourmpakisRongchao JinJ Colloid Interface Sci. 505, 1202 (2017)
  2. "Computational Insights into Adsorption of C4 Hydrocarbons in Cation-Exchanged ZSM-12 Zeolites," Pavlo Kostetskyy and Giannis Mpourmpakis, Ind. Eng. Chem. Res. 56, 7062 (2017)
  3. "Molecular “surgery” on a 23-gold-atom nanoparticle," Qi LiTian-Yi LuoMichael G. TaylorShuxin WangXiaofan ZhuYongbo SongGiannis MpourmpakisNathaniel L. Rosi and Rongchao Jin, Science Advances 3, e1, 603193 (2017)
  4. "CO2 activation on Cu-based Zr-decorated nanoparticles," Natalie Austin, Jingyun Ye and Giannis MpourmpakisCatal. Sci. Technol 7, 2245 (2017)
  5. "Potassium-Promoted Molybdenum Carbide as a Highly Active and Selective Catalyst for CO2 Conversion to CO," Marc D. Porosoff, Jeffrey W. Baldwin, Xi Peng, Giannis Mpourmpakis, Heather D. Willauer, ChemSusChem 10, 1 (2017)

Oxide-metal Interfaces as Active Sites for Acid-base Catalysis: Oxidation State of Nanocatalyst Change with Decreasing Size, Conversion of Heterogeneous to Homogeneous Catalysis, Hybrid Systems

Speaker(s): 
Gábor A. Somorjai
Dates: 
Friday, May 6, 2016 - 9:30am to 10:30am

When metal nanoparticles are placed on different mezoporous or microporous oxide supports the catalytic turnover rates and selectivities markedly change.  The charge flow between the metal and the oxide ionizes the adsorbed molecules at the oxide-metal interfaces and alters the catalytic chemistry (acid-base catalysis). 

The oxidation state of metal nanoparticles becomes less metallic and assume higher oxidation states with decreasing size.  The...

Metal Nanocatalysts, Their Synthesis and Size Dependent Covalent Bond Catalysis: Instrumentation for Characterization under Reaction Conditions

Speaker(s): 
Gábor A. Somorjai
Dates: 
Thursday, May 5, 2016 - 5:00pm to 7:00pm

Colloidal chemistry is used to control the size, shape and composition of metal nanoparticles usually in the 1-10 nm range.  In-situ methods are used to characterize the size, structure (electronic and atomic), bonding, composition and oxidation states under reaction conditions.  These methods include sum frequency generation nonlinear optical spectroscopy (SFG), ambient pressure X-ray photoelectron spectroscopy (APXPS) and high pressure scanning tunneling...

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Personal | Department
Department of Chemistry, University of Pittsburgh
Ph.D., Computational Organic Chemistry, University of California, 2010
Summary:

Reactivity and Selectivity Rules in Organic and Organometallic Reactions
We are developing computational models to quantitatively describe the origins of reactivity and selectivity in organocatalytic and transition metal-catalyzed reactions. We perform quantum mechanical calculations to explore the reaction mechanism, followed by thorough analysis on various stereoelectronic effects to predict how changes of the catalyst structure, substituents, and solvent affect rate and selectivity. We use quantitative energy decomposition methods to dissect the key interactions in the transition state and provide chemically meaningful interpretation to the computed reactivity and selectivity. We apply these computational studies to a broad range of organic and organometallic reactions, such as C–H and C–C bond activations, coupling reactions, olefin metathesis, and polymerization reactions. 

Catalyst Screening and Prediction
We are developing a multi-scale computational screening protocol which could efficiently rank the catalysts based on ligand-substrate interaction energies in the transition state. 

Applications of Computational Chemistry in Understanding Organic Chemistry
We are collaborating with experimental groups at Pitt and many other institutions to solve problems in organic chemistry using computational methods and programs. Our goal is to establish the most effective strategy to use modern computational methods and hardware to help address the grand challenges in synthetic chemistry. 

 

Most Cited Publications: 
  1. "Computational Studies of Ruthenium-Catalyzed Olefin Metathesis," Peng Liu, Buck LH Taylor, Jesus Garcia-Lopez, Kendall N Houk, Handbook of Metathesis, 2nd Edition, Volume 1: Catalyst Development and Mechanism (2015)
  2. "Computational Explorations of Mechanisms and Ligand-Directed Selectivities of Copper-Catalyzed Ullmann-Type Reactions," Gavin O. Jones, Peng Liu, K. N. Houk and Stephen L. Buchwald, J. Am. Chem. Soc. 132, 6205 (2010)
  3. "Suzuki−Miyaura Cross-Coupling of Aryl Carbamates and Sulfamates: Experimental and Computational Studies," Kyle W. Quasdorf, Aurora Antoft-Finch, Peng Liu, Amanda L. Silberstein, Anna Komaromi, Tom Blackburn, Stephen D. Ramgren, K. N. Houk, Victor Snieckus, and Neil K. Garg, J. Am. Chem. Soc. 133, 6352 (2011)
  4. "Z-Selectivity in Olefin Metathesis with Chelated Ru Catalysts: Computational Studies of Mechanism and Selectivity," Peng Liu, Xiufang Xu, Xiaofei Dong, Benjamin K. Keitz, Myles B. Herbert, Robert H. Grubbs, and K. N. Houk, J. Am. Chem. Soc. 134, 1464 (2012)
  5. "Palladium-Catalyzed Meta-Selective C–H Bond Activation with a Nitrile-Containing Template: Computational Study on Mechanism and Origins of Selectivity," Yun-Fang Yang, Gui-Juan Cheng, Peng Liu, Dasheng Leow, Tian-Yu Sun, Ping Chen, Xinhao Zhang, Jin-Quan Yu, Yun-Dong Wu, and K. N. Houk, J. Am. Chem. Soc. 136, 344 (2014)
Recent Publications: 
  1. "A redox-switchable ring-closing metathesis catalyst," Dominika N. Lastovickova, Aaron J. Teator, Huiling Shao, Peng Liu and Christopher W. Bielawski, Inorg. Chem. Front., 2017, Advance Article

  2. "The Origins of the Stereoretentive Mechanism of Olefin Metathesis with Ru-Dithiolate Catalysts", Jessica M. Grandner, Huiling Shao, Robert H. Grubbs, Peng Liu, and Kendall N. Houk, J. Org. Chem., Just Accepted Manuscript
  3. "Catalytic Intermolecular Carboamination of Unactivated Alkenes via Directed Aminopalladation," Zhen Liu, Yanyan Wang, Zichen Wang, Tian Zeng, Peng Liu, and Keary M. Engle, J. Am. Chem. Soc., 139 (32), 11261–11270 (2017)
  4. "Computational Study of Ni-Catalyzed C–H Functionalization: Factors That Control the Competition of Oxidative Addition and Radical Pathways," Humair M. Omer and Peng LiuJ. Am. Chem. Soc. 139, 9909 (2017)
  5. "NHC Ligands Tailored for Simultaneous Regio- and Enantiocontrol in Nickel-Catalyzed Reductive Couplings," Hengbin Wang, Gang Lu, Grant J. Sormunen, Hasnain A. Malik, Peng Liu, and John Montgomery, J. Am. Chem. Soc. 139, 9317 (2017)
  6. "Rhodium-Catalyzed Enantioselective Radical Addition of CX4 Reagents to Olefins", Bo Chen, Cheng Fang, Peng Liu, and Joseph M. Ready, Angew. Chem. 129, 1 (2017)
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Websites: 
Personal | Department
Department of Chemical and Petroleum Engineering, University of Pittsburgh
Ph.D., Chemistry, California Institute of Technology, 2007
Summary:

The Keith group applies and develops computational chemistry to study and discover solutions to problems at the interface of engineering and basic science.  They are currently focused on modeling chemical reaction mechanisms and the atomic scale of materials to help develop renewable energy and sustainability technologies.

The group uses quantum chemistry-based multiscale modeling to predict and study the atomic scale of materials and chemical reactions. With electronic structure and atomistic methods, they can investigate fundamental reaction steps at different time- and length-scales that would otherwise be difficult or impossible to investigate with experiment. 

Notably, their studies are entirely carried out in silico (on a computer) and almost entirely free from artificial biases that are present when using experimental inputs. Whether doing so alone or in collaboration with experimentalists, the group provides deep perspective on the atomic-scale of catalytic environments to understand how they work and how to further improve them.

The 'ground-up' multiscale modeling approach uses appropriate levels of quantum chemistry (QC) theory (typically on up to ca. 200 atoms) to model reaction energiesbarrier heightspKas, and standard redox potentials. Using data obtained from QC theory, they can also develop analytic reactive forcefields, which are capable of modeling reaction dynamics on systems on the order of 100,000 atoms. Reactive forcefield data in turn can be used to generate rate constant libraries for kinetic Monte Carlo (kMC) simulations to model larger time-scale and length-scale phenomena such a nanoparticle/material growth and ripening.

Most Cited Publications: 
  1. "Water Oxidation on Pure and Doped Hematite (0001) Surfaces: Prediction of Co and Ni as Effective Dopants for Electrocatalysis," Peilin Liao, John A. Keith, and Emily A. Carter, J. Am. Chem. Soc. 134, 13296 (2012)
  2. "The Mechanism of the Wacker Reaction: A Tale of Two Hydroxypalladations," John A. Keith, Patrick M. Henry, Angew. Chem. Int. Ed. 48, 9038 (2009)
  3. "Theoretical Studies of Potential-Dependent and Competing Mechanisms of the Electrocatalytic Oxygen Reduction Reaction on Pt(111)," John A. Keith, Timo Jacob, Angew. Chem. Int. Ed. 49, 9521 (2010)
  4. "Theoretical Investigations of the Oxygen Reduction Reaction on Pt(111)," John A. Keith, Gregory Jerkiewicz, Timo Jacob, ChemPhysChem 11, 2779 (2010)
  5. "Theoretical Elucidation of the Competitive Electro-oxidation Mechanisms of Formic Acid on Pt(111)," Wang Gao, John A. Keith, Josef Anton, and Timo Jacob, J. Am. Chem. Soc. 132, 18377 (2010)
Recent Publications: 
  1. "Quantum Chemical Analyses of BH4- and BH3OH- Hydride Transfers to CO2 in Aqueous Solution with Potentials of Mean Force," Mitchell C. Groenenboom, John Andrew Keith, ChemPhysChem 18, 1 (2017) 
  2. "Doped Amorphous Ti Oxides to Deoptimize Oxygen Reduction Reaction Catalysis," Mitchell C. Groenenboom, Rachel M. Anderson, Derek J. Horton, Yasemin Basdogan, Donald F. Roeper, Steven A. Policastro, and John A. KeithJ. Phys. Chem. C 121, 16825 (2017)
  3. "A Sobering Assessment of Classical Force Field Methods for Low Energy Conformer Predictions," Ilana Y. Kanal, John A. Keith, Geoffrey R. Hutchison, arXiv:1705.04308
  4. "Nitrogen-doped nanocarbon materials under electroreduction operating conditions and implications for electrocatalysis of CO2," Karthikeyan Saravanan, Eric Gottlieb, John A. KeithCarbon 111, 859 (2017)
  5. "Quantifying solvation energies at solid/liquid interfaces using continuum solvation methods," Corinne M. Gray, Karthikeyan Saravanan, Guofeng Wang & John A. Keith, Molecular simulations 43, 420 (2017)

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