Computational approaches to the determination of active site structures and reaction mechanisms in heterogeneous catalysts

We apply quantum chemical methods to the study of active site structures and reaction mechanisms in mesoporous silica and metal oxide catalysts. Our approach is based on the use of both molecular cluster and embedded cluster (QM/MM) techniques, where the active site and molecular complex are described using density functional theory (DFT) and the embedding matrix simulated by shell model potentials. We consider three case studies: alkene epoxidation over the microporous TS-1 catalyst; methanol synthesis on ZnO and Cu/ZnO and C–H bond activation over Li-doped MgO.

[1]  L. Pettersson,et al.  Gas-phase hydrogen abstraction from methane using metal oxides. Theoretical study , 1991 .

[2]  I. Vergara,et al.  Laser-induced-impurity colloid formation and dissociation in MgO single crystals , 1998 .

[3]  C. Catlow,et al.  Active sites for heterogeneous catalysis by functionalisation of internal and external surfaces , 2004 .

[4]  O. Schirmer Trapped-hole centers containing lithium in MgO, CaO and SrO , 1970 .

[5]  M. Tardío,et al.  p -type semiconducting properties in lithium-doped MgO single crystals , 2002, cond-mat/0201502.

[6]  F. Rey,et al.  Heterogeneous catalysts obtained by grafting metallocene complexes onto mesoporous silica , 1995, Nature.

[7]  J. Lunsford Recent Advances in the Oxtoattve Coupling of Methane , 1994 .

[8]  David C. Forbes,et al.  Catalytic Epoxidation of Alkenes with Oxone. , 1995 .

[9]  K. Aika,et al.  Interaction of water with 1% Li/MgO: dc conductivity of Li/MgO catalyst for methane selective activation , 1995 .

[10]  S. C. Rogers,et al.  QUASI: A general purpose implementation of the QM/MM approach and its application to problems in catalysis , 2003 .

[11]  G. Froment,et al.  Nature of formate in methanol synthesis on Cu/ZnO/A2O3 , 1994 .

[12]  T. Maschmeyer,et al.  Probing the Titanium Sites in Ti−MCM41 by Diffuse Reflectance and Photoluminescence UV−Vis Spectroscopies , 1997 .

[13]  Gopinathan Sankar,et al.  Determining the structure of active sites, transition states and intermediates in heterogeneously catalysed reactions. , 2002, Chemical communications.

[14]  Tomoko Watanabe,et al.  Adsorption of methane on magnesium oxide studied by temperature-programmed desorption and ab initio molecular orbital methods , 1991 .

[15]  M. Sinev Free radicals in catalytic oxidation of light alkanes: kinetic and thermochemical aspects , 2003 .

[16]  J. Lercher,et al.  Oxidative conversion of propane over lithium-promoted magnesia catalyst. I. Kinetics and mechanism , 2003 .

[17]  F. Finocchi,et al.  First principles studies of complex oxide surfaces and?interfaces , 2004 .

[18]  C. Rao,et al.  Interaction of CO with Cu/ZnO catalyst surfaces prepared in situ in the electron spectrometer : evidence for CO2- and related species relevant to methanol synthesis , 1998 .

[19]  A. Becke Density-functional thermochemistry. V. Systematic optimization of exchange-correlation functionals , 1997 .

[20]  F. Illas,et al.  Bonding of NH3, CO, and NO to NiO and Ni-doped MgO: a problem for density functional theory , 2004 .

[21]  C. Catlow,et al.  Computer simulation of alkali metal trapped hole defects in alkaline earth oxides , 1988 .

[22]  J. Narayan,et al.  Oxidation and reduction of lithium-containing MgO at high temperatures , 1978 .

[23]  Gang Liu,et al.  Effects of Li impurities on MgO ( 001 ) , 2002 .

[24]  M. Abraham,et al.  RADIATION-INDUCED [Na]$sup 0$ CENTERS IN MgO AND SrO. , 1972 .

[25]  C. Catlow,et al.  Defect processes at low coordinate surface sites of MgO and their role in the partial oxidation of hydrocarbons , 1995 .

[26]  M. Alfredsson,et al.  Understanding the interface between oxides and metals. , 2003, Faraday discussions.

[27]  C. Catlow,et al.  Potential models for ionic oxides , 1985 .

[28]  M. Abraham,et al.  Electron-nuclear-double-resonance investigations of [ Li ] 0 and [ Na ] 0 centers in MgO, CaO, and SrO , 1974 .

[29]  A. Hervé,et al.  Endor spectrum of the VLi center in MgO at 4.2°K , 1974 .

[30]  V. Choudhary,et al.  Acidity/basicity of rare-earth oxides and their catalytic activity in oxidative coupling of methane to C2-hydrocarbons , 1991 .

[31]  P. Sherwood,et al.  Metal Cluster Support Interactions in the Cu/ZnO System: A QM/MM Study , 2003 .

[32]  M. Gillan,et al.  Assessment of competing mechanisms of the abstraction of hydrogen from CH , 2004 .

[33]  J. T. Ranney,et al.  The Surface Science of Metal Oxides , 1995 .

[34]  A. Shluger,et al.  Quantum-chemical simulation of impurity-induced trapping of a hole: (Li)0 centre in MgO , 1986 .

[35]  A. Schäfer,et al.  Fully optimized contracted Gaussian basis sets of triple zeta valence quality for atoms Li to Kr , 1994 .

[36]  C. Catlow,et al.  Interionic potentials in ionic solids , 1982 .

[37]  C. Catlow,et al.  On the structure and coordination of the oxygen-donating species in Ti↑MCM-41/TBHP oxidation catalysts: a density functional theory and EXAFS study , 2002 .

[38]  R. Vila,et al.  Evidence for schottky barrier formation due to hole centers in Al2O3:Mg and MgO:Li with metal contacts , 1995 .

[39]  P. Sherwood,et al.  Hybrid QM/MM embedding approach for the treatment of localized surface states in ionic materials , 2004 .

[40]  A. W. Overhauser,et al.  Theory of the Dielectric Constants of Alkali Halide Crystals , 1958 .

[41]  R. Orlando,et al.  Hydrogen abstraction from methane by Li doped MgO: A periodic quantum mechanical study , 1996 .

[42]  M. Bowker,et al.  Mechanism and kinetics of methanol synthesis on zinc oxide , 1981 .

[43]  M. Blomberg,et al.  Methods and models for studying mechanisms of redox-active enzymes , 2005, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[44]  G. Sankar,et al.  The role of synchrotron-based studies in the elucidation and design of active sites in titanium-silica epoxidation catalysts. , 2001, Accounts of chemical research.

[45]  John Meurig Thomas Introductory lecture. Catalysis and surface science at high resolution , 1996 .

[46]  K. Aika,et al.  Temperature-programmed desorption study of water-gas shift and methane steam-reforming reactions over Li/MgO catalyst , 2000 .

[47]  R. Orlando,et al.  Trapped-hole centres containing lithium and sodium in MgO, CaO and SrO. An ab initio supercell study , 1998 .

[48]  R. Orlando,et al.  Lithium trapped-hole centre in magnesium oxide. An ab initio supercell study , 1998 .

[49]  J. Lercher,et al.  Oxidative conversion of propane over lithium-promoted magnesia catalyst. II. Active site characterization and hydrocarbon activation , 2003 .

[50]  A. Rohl MARVIN: a new computer code for studying surfaces and interfaces and its application to calculating the crystal morphologies of corundum and zircon , 1995 .

[51]  John Meurig Thomas The Ineluctable Need for in Situ Methods of Characterising Solid Catalysts as a Prerequisite to Engineering Active Sites , 1997 .

[52]  M. Dixon,et al.  Interionic potentials in alkali halides and their use in simulations of the molten salts , 1976 .

[53]  J. Lunsford,et al.  Formation of gas-phase methyl radicals over MgO , 1985 .

[54]  M. Sinev Kinetic modeling of heterogeneous-homogeneous radical processes of the partial oxidation of low paraffins , 1995 .

[55]  F. Weigend,et al.  Gaussian basis sets of quadruple zeta valence quality for atoms H–Kr , 2003 .

[56]  J. Narayan,et al.  Transmission electron microscope studies on Li-doped MgO , 1978 .

[57]  A. Shluger,et al.  Relative energies of surface and defect states: ab initio calculations for the MgO (001) surface , 2000 .

[58]  Hans W. Horn,et al.  Fully optimized contracted Gaussian basis sets for atoms Li to Kr , 1992 .

[59]  M. Born,et al.  Dynamical Theory of Crystal Lattices , 1954 .

[60]  G. M. Zhidomirov,et al.  Active centres of magnesium oxide surface and calculations of dissociative chemisorption of methane on modified MgO , 1992 .

[61]  S. C. Rogers,et al.  Assignment of the complex vibrational spectra of the hydrogenated ZnO polar surfaces using QM/MM embedding , 2003 .

[62]  L. Pettersson,et al.  Hydrogen abstraction from methane on a magnesia (001) surface , 1991 .

[63]  T. Fujitani,et al.  Evidence for a special formate species adsorbed on the Cu–Zn active site for methanol synthesis , 1998 .

[64]  J. Lunsford CATALYTIC CONVERSION OF METHANE TO MORE USEFUL CHEMICALS AND FUELS: A CHALLENGE FOR THE 21ST CENTURY , 2000 .

[65]  V. Korchak,et al.  Oxidative coupling of methane with participation of oxide catalyst lattice oxygen , 1990 .

[66]  C. Catlow,et al.  The Three-Dimensional Structure of the Titanium-Centered Active Site during Steady-State Catalytic Epoxidation of Alkenes , 2001 .

[67]  Gilbert F. Froment,et al.  A DRIFTS study of the morphology and surface adsorbate composition of an operating methanol synthesis catalyst , 1994 .

[68]  Donald G. Truhlar,et al.  Tests of second-generation and third-generation density functionals for thermochemical kineticsElectronic supplementary information (ESI) available: Mean errors for pure and hybrid DFT methods. See http://www.rsc.org/suppdata/cp/b3/b316260e/ , 2004 .

[69]  Maria-Aglaia D. Stiakaki,et al.  Theoretical aspects of methane chemisorption on MgO surfaces. Modelling of impurity-induced trapping of a hole, surface defects and site dependence of methane chemisorption on (MgO)9,12 clusters , 1996 .

[70]  B. Henderson,et al.  Optical and EPR Studies of [Na] 0 and [Li] 0 Centers in CaO , 1972 .

[71]  A. Shluger,et al.  Modeling charge self-trapping in wide-gap dielectrics: Localization problem in local density functionals , 2002, cond-mat/0205218.

[72]  Konstantin M. Neyman,et al.  FTIR Spectroscopic and Density Functional Model Cluster Studies of Methane Adsorption on MgO , 1998 .

[73]  K. C. Waugh,et al.  Promotion of methanol synthesis and the water-gas shift reactions by adsorbed oxygen on supported copper catalysts , 1987 .

[74]  J. Thomas Catalysis and Surface Science at High Resolution , 1997 .

[75]  H. Grönbeck First Principles Studies of Metal-Oxide Surfaces , 2004 .

[76]  R. Orlando,et al.  Catalytic properties of F-centres at the magnesium oxide surface : Hydrogen abstraction from methane , 1997 .

[77]  Alexey A. Sokol,et al.  From CO2 to methanol by hybrid QM/MM embedding , 2001 .

[78]  Fred A. Hamprecht,et al.  Development and assessment of new exchange-correlation functionals , 1998 .

[79]  C. Catlow,et al.  Computational and EXAFS Study of the Nature of the Ti(IV) Active Sites in Mesoporous Titanosilicate Catalysts , 1997 .

[80]  G. Pacchioni,et al.  Theoretical description of hole localization in a quartz Al center: The importance of exact electron exchange , 2000 .

[81]  C. Catlow,et al.  Surface structure of zinc oxide (1010), using an atomistic, semi-infinite treatment , 2002 .

[82]  R. Burch,et al.  C-H Bond Activation in Hydrocarbon Oxidation on Solid Catalysts , 1996 .

[83]  R. Burch,et al.  CH bond activation in hydrocarbon oxidation on solid catalysts , 1995 .

[84]  W. Green,et al.  Upper bound on the yield for oxidative coupling of methane , 2003 .

[85]  J. Narayan,et al.  High-temperature and ionization-induced effects in lithium-doped MgO single crystals , 1977 .

[86]  Julian D. Gale,et al.  GULP: A computer program for the symmetry-adapted simulation of solids , 1997 .

[87]  T. Truong,et al.  An ab Initio Study on the Oxidative Coupling of Methane over a Lithium-Doped MgO Catalyst: Surface Defects and Mechanism , 1997 .