Main Application Areas of Precious Metal Catalysts
Briefly introduce the main application areas of precious metal catalysts.
Main Application Areas of Precious Metal Catalysts
Precious metal catalysts (Pt, Pd, Rh, etc.) occupy a core position in environmental protection, chemical production, and energy fields due to their high activity and low ignition temperature.
Environmental Protection
VOCs Treatment: Pt-Pd bimetallic catalysts completely oxidize benzene compounds, esters, and other VOCs to CO₂ and H₂O at 200-400℃, achieving a removal rate of ≥98%, saving 50%-70% energy, and eliminating secondary NOx pollution.
Automotive Exhaust Purification: Three-way catalytic converters use Pt, Pd, and Rh to convert CO, HC, and NOx; Pt is used to oxidize CO and HC in diesel vehicles, and Pt/Pd is used in SCR to promote NOx reduction.
Indoor Air Purification: Pt/Pd supported on activated carbon or molecular sieves decomposes formaldehyde and benzene into CO₂ and H₂O at room temperature, used in air purifiers and air conditioning systems.
Chemical Production Sector
Petrochemicals: Pt-Re/Pt-Sn catalysts are used in catalytic reforming (naphtha → high-octane gasoline, aromatics); Pd/Pt is used in hydrorefining (desulfurization, denitrification, dearomatics).
Fine Chemicals: Pd/C is used for selective hydrogenation of unsaturated bonds (vegetable oil, nitrobenzene hydrogenation); Pt is used for alcohol oxidation to aldehydes/ketones (e.g., ethylene oxidation to acetaldehyde).
Basic Chemicals: Pt-Rh mesh is used for ammonia oxidation to nitric acid; Ag catalysts are used for ethylene oxidation to ethylene oxide (non-precious metal, often discussed together).
Energy Sector
Fuel Cells: Pt/C is the core material of PEMFCs, used in hydrogen-oxygen electrocatalytic reactions to directly convert chemical energy into electrical energy.
Hydrogen Production: WGS uses Pt/CeO₂ to convert CO to H₂; methane steam reforming is mainly Ni-based, with precious metals used to improve stability.
Core Requirements for Each Sector
Application Areas | Key Requirements | Major Failure Risks |
VOCs Treatment | Low ignition temperature, poisoning resistance | S/Cl poisoning, high-temperature sintering |
Automotive Exhaust | Good thermal stability | High-temperature sintering, Pb poisoning |
Catalytic Reforming | Anti-carbon buildup, long lifespan | Carbon buildup, S poisoning |
Fine Hydrogenation | High selectivity | Loss of active components |
Fuel Cells | High dispersion, good durability | CO poisoning, Pt agglomeration |
Usage and Selection
VOCs treatment and automotive exhaust purification are the two largest applications of precious metal catalysts, accounting for over 60% of the market combined.
VOCs Treatment: Pt-Pd bimetallic catalysts are the most versatile, balancing activity and cost.
Automotive Exhaust: Pt-Pd-Rh ternary systems are irreplaceable.
Fine Hydrogenation: Pd/C is the dominant system, offering excellent selectivity and activity.
Summary
The applications of precious metal catalysts can be summarized into three major sectors: environmental governance (VOCs, automotive exhaust), chemical production (reforming, hydrogen refueling), and energy (fuel cells, hydrogen production). VOCs treatment and automotive exhaust purification are the core markets. Selection must be based on specific operating conditions (temperature, toxic substances, lifespan requirements) to match the type of precious metal. Pt-Pd bimetallic catalysts are the preferred choice for VOCs treatment. Although the initial cost is high, the overall benefits brought by high activity and long lifespan far outweigh those of non-precious metal systems.