The difference between precious metal catalysts and VOCs catalysts lies in their composition, application scope, and performance characteristics:

1. Composition:

• Precious Metal Catalysts:
  Composed of rare, high-value metals such as platinum (Pt), palladium (Pd), rhodium (Rh), or ruthenium (Ru). These materials are chosen for their exceptional catalytic activity and stability.

• VOCs Catalysts:
  Defined by their function (treating volatile organic compounds), these catalysts can include both precious metals and non-precious materials like transition metal oxides (e.g., copper, manganese, vanadium) or zeolites. They are not restricted to a specific material type.

2. Application:

• Precious Metal Catalysts:
  Used in diverse applications beyond VOCs treatment, such as automotive catalytic converters (reducing CO, NOx, and hydrocarbons), chemical synthesis (e.g., hydrogenation), and fuel cells.

• VOCs Catalysts:
  Specialized for oxidizing or reducing VOCs in industrial emissions, paint, coatings, or waste gases. They target organic pollutants like benzene, formaldehyde, or toluene, converting them into CO₂, H₂O, or less harmful substances.

3. Performance and Cost:

• Precious Metal Catalysts:

  • Advantages: High efficiency at lower temperatures, long lifespan, and broad reactivity.

  • Drawbacks: Expensive and sensitive to poisoning (e.g., by sulfur or lead).

• Non-Precious VOCs Catalysts:

  • Advantages: Lower cost and better resistance to poisons.

  • Drawbacks: Often require higher operating temperatures and may degrade faster.

4. Overlap:

• Precious metals are frequently used in VOCs catalysts due to their effectiveness, but VOCs catalysts also encompass cheaper alternatives. Thus, VOCs catalysts are defined by their purpose, while precious metal catalysts are defined by their material composition.