Ammonia Synthesis

Abstract The sections in this article are Introduction Some Basic Considerations Catalyst Materials: Iron and Ruthenium Ammonia Synthesis as the Reference Reaction Choice of Catalyst: Historic Development Choice of Catalyst: Theory‐Based Approach Reaction Efficiency and Research Needs Thermodynamic Aspects Di‐Nitrogen Nitrides Hydrogen The Reaction Phase Diagrams Ruthenium Substrates Generation and Structure of “Ammonia Iron” Reference Experiments Structure of the Oxide Precursor Activation Process Activated Catalyst: Microtexture Activated Catalyst: Microstructure Nature of the Iron Catalyst Abundance of Active Sites Single Crystal Approach in the Iron System Single‐Crystal Structures Energetics of Hydrogen and Nitrogen Chemisorption Structure and Energetics of Chemisorbed Ammonia Kinetics of Nitrogen Chemisorption Potassium Promoter Effect Polycrystalline Substrates The Material Gap: Alumina as Promoter Nitrogen Chemisorption on Model Systems Nitrogen Chemisorption on Polycrystalline Substrates Non‐Fe Systems: Ru Catalysts Nanostructured Ru Surface‐Science Studies of the Ru System Mechanism of Ammonia Synthesis Basic Kinetic Information Analytical Rate Expressions Microkinetic Models Conclusions