Contents1 The Harm of NOx and Its Emission 11.1 NOx 11.1.1 The Characteristic of NOx 11.1.2 The Harm of NOx 21.2 The Formation Mechanism of NOx 41.2.1 NOx Formation Mechanism and the Interfering Factors 41.2.2 Sources of NOx 6References 82 NOx Emission Control Technologies (NOx Emission Abatement) 112.1 Introduction 112.1.1 Pre-combustion and Combustion Modification 112.1.2 Post-combustion Methods 132.2 SCR Process Configurations 142.2.1 HD-SCR Configuration 152.2.2 LD-SCR Configuration 172.2.3 TE-SCR Configuration 172.3 Low-Temperature SCR Catalyst 172.4 Low-Temperature SCR Mechanism 192.4.1 Eley-Rideal (E-R) Mechanism 192.4.2 L-H Mechanism 202.5 Application of Density Functional Theory (DFT) in the Study of Low Temperature SCR Catalyst 21References 223 Preparation of Catalysts 253.1 General Process of NH3-SCR Catalysts Preparation 253.2 Precipitation Method 253.2.1 Precipitating Classical Theory 263.2.2 Factors Affecting Catalyst Performance in the Precipitation Method 283.2.3 Brief Conclusion 303.3 Sol-Gel Method 303.3.1 Fundamentals of Sol-Gel Process 313.3.2 Sol-Gel Methods for Preparing Supported Metals 313.3.3 Brief Conclusion 333.4 Impregnation Method 333.4.1 Impregnating Solution Preparation 343.4.2 The Influencing Factors of the Impregnation Method 353.4.3 Brief Conclusion 363.5 Hydrothermal Method 363.5.1 Basic Concepts of Hydrothermal Method 363.5.2 Principles of Hydrothermal Synthesis Methods 373.5.3 Brief Conclusion 38References 39Catalyst Characterization 414.1 Electron Microscopy 414.1.1 Scanning Electron Microscope (SEM) 414.1.2 Transmission Electron Microscope (TEM) 434.2 BET Surface Area 464.2.1 BET Theory 464.2.2 The Calculations of BET Surface Area 484.2.3 Drawbacks and Limitations 484.3 X-Ray Diffraction Techniques 494.3.1 Foundations of Crystallography 494.3.2 Powder XRD Diffraction Analysis 514.3.3 Application of X-Ray Diffraction in Catalyst Research 524.4 X-Ray Photoelectron Spectroscopy Techniques 554.4.1 The Features of XPS Spectra 564.4.2 Case Study 564.5 Temperature-Programmed Analysis Technique 584.5.1 Temperature-Programmed Desorption (TPD) 584.5.2 Temperature-Programmed Reduction (TPR) 604.6 Raman Spectroscopy 614.6.1 Basic Principles of Analysis 62References 64MnOx-Based SCR Catalyst 695.1 Introduction 695.2 Single Manganese Oxide Catalysts 705.2.1 Effect of Oxidation State and Crystal Structure on Catalytic Performance 705.2.2 Effect of Specific Surface Area and Surface Acidity on Catalytic Performance 715.2.3 Effect of Morphology and Exposed Crystalline Surfaces on Catalytic Performance 725.3 Multi-metal Manganese Oxide Catalysts 735.4 Supported Manganese Oxide-Based Catalysts 775.4.1 MnOx-Based Catalysts Supported on Ti02 785.4.2 MnOx-Based Catalysts Supported on AI2O3 815.4.3 MnOx-Based Catalysts Supported on Carbon Materials 82References 83Ceria-Based SCR Catalysts 876.1 Introduction 876.2 Single Ceria-Based Catalysts 886.2.1 Effect of Precursor and Calcination Temperature on Catalytic Performance 886.2.2 Effect of Preparation Method on Catalytic Performance 906.2.3 Effect of Morphology and Exposed Crystalline Surfaces on Catalytic Performance 926.3 Composite Ceria-Based Catalysts 936.3.1 Mn-Ce Composite Oxide System 936.3.2 Ce-Cu Composite Oxide System 946.3.3 Ce-Ti Composite Oxide System 956.4 Supported Ceria-Based Catalysts 976.4.1 CeO2 as the Support 976.4.2 CeO2 as the Surface Loading Component 97References 102Cu-Based and Fe-Based SCR Catalysts 1057.1 Introduction 1057.2 Cu-Based SCR Catalysts 1057.2.1 Copper Oxide-Based Catalyst 1057.2.2 Copper Based Molecular Sieve Catalyst 1067.2.3 Core-Shell Structure in Copper Based NH3-SCR Catalysts 1077.3 Fe-Based SCR Catalysts 1097.3.1 Iron Oxide-Based Catalyst 1097.3.2 Fe Based Molecular Sieve 112References 112Chemical Deactivation and Resistance of Low-Temperature SCR Catalyst 1158.1 Introduction 1158.2 Deactivation Mechanism of SCR Catalysts by Various Elements 1168.2.1 S02 and H20 1168.2.2 Alkali Metals/Alkali-Earth Metals 1208.2.3 Heavy Metals 1218.3 Deactivation Resistance 1238.3.1 Resistance to SO2 or/and H2O Poisoning 1238.3.2 Resistance to Alkali/Alkaline Metal Poisoning 1258.3.3 Resistance to Heavy Metal Poisoning 126References 128