Q2. What future works have the authors mentioned in the paper "Correlation of static ageing effects on automotive catalysts" ?
Further work on dynamic ageing must be conducted in order to see if any correlation exists between static ageing and dynamic ageing under laboratory conditions.
Q3. What is the common method of reducing automotive exhaust emissions?
The three-way catalytic converter is the most common method of reducing these emissions and uses precious metals such as Pt, Pd or Rh, as the catalytic material.
Q4. Why is the QUB global catalyst simulation model becoming critical?
Due to the increasing complexity of modern automotive aftertreatment systems, and the slow and expensive nature of testing and ageing catalyst samples on-road or on an engine test bench, much more rapid laboratory testing and ageing methods, as well as computer simulation models are now becoming a critical part of the automotive catalyst design phase.
Q5. What is the reason for the light-off variation between samples?
It is predicted that the light-off variation between samples is due to a variation in precious metal particles from one core to the next, which is also indicated by the initial baseline light-off test results.
Q6. What is the effect of static ageing on the engine?
Static ageing in air has been shown to cause increased ageing due to temperature than predicted by the BAT equation, but less due to time.
Q7. What was the ageing procedure for the cored samples?
After the baseline light-off tests had been carried out on all of the de-greened cored samples, static ageing was conducted in a furnace oven, in air, for ageing temperatures and times calculated using the BAT equation.
Q8. How much of the light-off shift should be 5% of the initial performance?
by using the BAT equation, with the activation energy for CO oxidation of approximately 100 kJ/mol,[17] it is estimated that the performance after 23.6 hours should only be 5% of the initial performance.
Q9. How long does the light-off shift occur after the initial ageing?
After the initial 1.18 hours of ageing, it can be seen that most ageing occurs in the first 11.8 hours (100 hours equivalent on a RAT-A cycle), with a light-off shift of 11 ᵒC being observed.
Q10. What is the process for generating a simulated exhaust gas?
The Horiba SIGU 2000 Series Gas Generator and Catalyst Test System generates a simulated exhaust gas, and temperature profile, to allow testing and evaluation of catalyst samples.
Q11. What was the effect of light-off tests on catalysts?
Light-off tests conducted by Fernandes et al.[8] showed shifts in light-off to higher temperatures as the ageing time was increased at ageing temperatures of 900 ᵒC and 1200 ᵒC. Yang[13] showed the effect that ageing time had for a dynamically aged catalyst.
Q12. What is the ageing temperature of the catalyst?
From the BAT equation it would be expected that as the ageing time increases the catalyst activity decreases, with a corresponding increase in light-off temperature.
Q13. What is the role of the catalytic converter in the automotive industry?
Regulations for automotive exhaust emissions are becoming more stringent, requiring the development of more effective catalytic control systems.
Q14. What is the difference between static and engine ageing?
even though static ageing at 1000 ᵒC has shown a decrease in catalytic activity with respect to ageing time, it is occurring at a much slower rate than when compared to engine ageing as defined by the BAT equation.
Q15. What is the R factor for the standard bench cycle?
The EPA recommends an R factor for the standard bench cycle of between 17500 and 18500, depending on the vehicle type, however if a different ageing cycle is used the R value is expected to be different.