1st Edition

Electron Microscopy in Heterogeneous Catalysis

By P.L Gai, E.D Boyes Copyright 2003

    Catalysis is one of the most important technologies in the industrial world, controlling more than 90% of industrial chemical processes and essential for large-scale production of plastics and fuel. Exploring the most common type of catalysis used in industry, Electron Microscopy in Heterogeneous Catalysis provides a coherent account of heterogeneous catalytic processes and catalyst surface structure at the atomic scale as elucidated by electron microscopy techniques.

    The book addresses a number of issues that are fundamental to the understanding of heterogeneous catalysis by oxides and supported metals. The properties of a catalyst are governed by its microstructure and chemistry on an atomic scale, and electron microscopy methods are essential to directly analyze these properties. The book provides important information about active species, metastable-transient species, mechanisms of particle catalysis sintering, promoter-poisoning effects on an atomic scale, and catalyst support interactions on a microscale.

    Preface and Acknowledgements

    AN INTRODUCTION TO HETEROGENEOUS CATALYSIS AND CATALYST STRUCTURES
    Science and technology of catalysis
    Fundamental principles of catalysis: some basic definitions
    Electronic configurations and quantum theory
    Chemical bonding
    Thermodynamic definitions relevant to catalysis and the role of electron microscopy
    Structure and chemistry of carbons and hydrocarbons
    Catalysis and band theory
    Some important structures of solid catalysts
    Carbons as supports in catalysis and new forms of carbons with atomic scale building blocks
    Oxides and nonstoichiometry in catalysis and the unique role of electron microscopy
    Catalysis by oxides
    Extended defects and crystallographic shear

    ELECTRON MICROSCOPY AND DIFFRACTION IN HETEROGENEOUS CATALYSIS
    Background
    Imaging in the TEM
    Surface profiling in HRTEM
    Chemical composition analysis of catalysts in the EM
    Electron energy loss spectroscopy (EELS)
    Convergent beam electron diffraction (CBED)
    The development of in situ environmental TM (ETEM) under controlled reaction environments to probe catalysis at the atomic level
    Novel wet-ETEM development for nanoscale studies of liquid-catalyst reactions at operating temperatures
    Scanning EM (SEM), cathodoluminescence in catalysis and environmental SEM (ESEM)
    Scanning transmission EM (STEM)-recent advances
    Image processing
    Other developments
    Parallel chemical studies and correlations with the catalyst microstructure

    ELECTRON MICROSCOPY STUDIES OF CATALYSIS BY OXIDES
    Single and mixed metal oxide systems: Redox pathways and anion deficiency
    Single metal oxide catalysts: MoO3
    In situ direct observations of surface defect structures in catalysts under controlled reducing environments and methods for defect analysis
    Shear domains and crystallographic shear (CS) planes in catalytic reduction
    Electron microscopy and defect thermodynamics: a new understanding of oxidation catalysis
    The role of defects in catalytic reactions
    Multi-component (practical) oxide catalysts
    Iron molybdates in methanol oxidation reactions
    Vanadium phosphate (V-P-O) catalysts for butane oxidation technology: the elucidation of active sites by in situ electron microscopy
    Examples of other mixed metal oxide systems
    Electronic structure of crystallites and dopant distributions by cathodoluminescence electron microscopy
    Zirconia (ZrO2)-based solid-acid catalysts and ceria (CeO2) systems
    The key role of electron microscopy in the discovery of novel reaction mechanisms in selective oxidation catalysis
    Stable silica-based ceramic oxide supports for catalysts: some recent developments

    CATALYSIS BY ZEOLITES AND MOLECULAR SIEVES
    Structures, acidity, and uses of zeolites
    Silicalites and aluminophosphates
    Determining three-dimensional structures by ED and HRTEM: MALPO solid acid catalysts

    CATALYSIS BY SUPPORTED METAL PARTICLES
    Recent developments
    Facile versus structure-sensitive reactions
    Preparation and characterization of model and practical metallic catalysts
    Catalytic mechanisms on supported metals
    Experimental studies by electron microscopy
    Small particles in HRTEM
    Experimental and theoretical developments in small metal particle catalysis using electron microscopy
    Structure of small metal particles
    EM studies of chemical interactions at metal-support interfaces
    Metal-support interactions
    In situ ETEM studies of metal-irreducible ceramic support interactions
    Methanol synthesis and oxidation reactions
    Monometallic nanocatalyst systems: copper nanocatalysts supported on silica (Cu/SiO2)
    Bimetallic or alloy systems: atomic structure and composition
    Fischer-Tropsch and Ziegler Nutta catalysis

    ENVIRONMENTAL CATALYSIS AND CATALYST DESIGN
    Perovskite-based catalysts for environmental pollution control: the role of electron microscopy
    High temperature superconducting cuprates (HTSC) as catalysts
    Hydrodesulfurization (HDS) catalysis
    Nanocatalysts in emission control, steam reforming, photocatalysis, and fuel cell catalysis
    Nanocatalysts for alternatives to chlorofluorocarbons (CFC)
    Concluding remarks

    References
    Index

    Biography

    P L Gai, DuPont, Central Research and Development, Wilmington, DE, USA and University of Delaware, Department of Materials Science and Engineering, Newark, USA, formerly at the University of Cambridge E D Boyes, DuPont, Central Research and Development, Wilmington, USA (and formerly University of Oxford).

    "This book deals with in situ dynamic observation and analysis of heterogeneous catalysis using environmental cells (EC) in transmission (TEM) and scanning electron microscopes (SEM). In general, it is based on outstanding and unique works carried out by the authors themselves over the past three decades, who pioneered this key enabling area of materials science. It provides comprehensive and yet compact introductions to heterogeneous catalysis and electron microscopy and diffraction, followed by detailed descriptions of electron microscopy studies of oxide catalysis, zeolites, molecular sieves, supported small metal particles, and environmental catalysis. For those who are carrying out in situ dynamic studies of catalysis using EC in TEM and/or SEM, this book gives a state-of-the-art review of this field. More importantly, this book encourages those catalysis students and electron microscopists who are planning to perform in situ dynamic studies of catalysis."
    -Professor Hiroyasu Saka, Nagoya University, Japan

    "P.L. Gai and E.D. Boyes have produced an authoritative text … [that is] indispensable if this is your subject."
    -P. Hawkes, Ultramicroscopy 101 (2004): 73-103