What is the role of d-block elements in industrial catalysis?

D-block elements are important as catalysts in industry because:

1. They can change oxidation states easily
   • This helps reactions happen faster without the metal being used up.
   • Example: Iron in making ammonia (Haber process).
2. They can form temporary compounds with reactants
   • These complexes make it easier for reactions to occur.
   • Example: Nickel in hydrogenation of vegetable oils.
3. They have active surfaces
   • Solid metals like platinum and palladium let gases or liquids stick to their surface, speeding up reactions.
   • Example: Catalytic converters in cars.
4. They can work in different ways
   • Homogeneous catalysts: Dissolve in the reaction (like some rhodium compounds).
   • Heterogeneous catalysts: Solid metals that act on the surface (like iron, nickel, platinum).

Simple summary:
D-block elements help reactions happen faster by changing oxidation states, forming complexes, or providing active surfaces.