Catalyst Aging – Our Most Frequently Asked Questions Answered

• Thermal deactivation: High temperature exposure can cause the catalyst to lose efficiency due to several factors, like:
  • Prolonged exposure to high exhaust temperatures can sinter the precious metal particles, reducing active surface area.
  • Thermal cycling (heating and cooling) can crack the substrate or washcoat.
• Chemical poisoning: Exposure to contaminants, such as additives, fuel and oil, can cause the catalyst to lose efficiency. Sulfur and phosphorus are some of the common contaminants.
• Mechanical Damage: Vibration, shock, or poor mounting can fracture or loosen the substrate.
• Physical Damage: Damage to catalyst cells, damage or reduction of catalyst wash coat, buildup of contaminants that prevent or block flow to the cell surfaces.
• Soot and Ash Accumulation: Particulate buildup restricts flow and covers active surfaces.

Catalyst aging is important because it ensures catalysts remain effective throughout their intended service life. It also provides OEMs and manufacturers with a way to simulate aging in a shorter timeframe, accelerating development. Additionally, governing bodies require that catalysts operate and perform reliably for the full duration of their certified service life.

• Regulatory Compliance – Emission regulations require catalysts to meet standards over defined lifespans
• Warranty Risk – Early aging can lead to costly replacements and damage brand reputation.
• Material Cost Optimization – Balancing precious metal loadings to meet both performance and durability requirements.
• Customer Satisfaction – Maintaining consistent performance over the product’s intended life cycle.

For the United States, there are 2 main regulatory bodies. The EPA (Environmental Protection Agency) and CARB (California Air Resources Board). While each body has its own requirement and standards, they both ensure that the catalysts are tested and can achieve their expected service life. International regulatory bodies also have their own requirements, such as Europe’s Euro7.

While new technologies continue to emerge, several established methods are commonly used to age a catalyst or catalyst system – each requiring its own specialized equipment. At TRP Laboratories, we use our patented C-FOCAS^® burners, while other methods can include:

• Chassis Dyno
• Engine Dyno
• Burner
• Oven/Kiln
• Specialized Reactors

For us at TRP Labs, we use our CFOCAS® aging rigs to accelerate the catalyst aging to real-world use levels using a variety of cycles from OEM’s to regulation standards.

• The duration of catalyst aging can vary based on the method in which you are aging them. Our CFOCAS^® aging takes less, but a different amount of time than a chassis dyno aging could take.
• Most tests range from 50 hours, up to several hundred hours based on different variables. Some of these variables are below
  • Vehicle type
  • Engine size
  • Mileage target
  • Regulation specific targets (EPA, CARB, Euro7)

Yes, they are different. Catalyst aging is the process where a catalysts performance reduces over time, caused by thermal, chemical and physical factors. Catalyst testing is when the catalyst is tested for performance, or efficiency. This performance and efficiency can be tested before, during and after catalyst aging. We often perform these tests before, during and after to determine the catalysts performance as it ages.

Yes, these catalysts can be tested using the same regulations/protocols as OEM catalysts. In fact, both the EPA and CARB also require these catalysts to be tested to ensure they meet specific aftermarket durability and emission standards.