Use of Transition Metals to Reduce Cold Start HC Emissions

Kevin  Guo, Ford Motor Company

 

Use of Transition Metals to Reduce Cold Start HC Emissions

 Authors:

 Kevin Guo, Giovanni Cavataio, Hungwen Jen, Rachael Harrington, Lifeng Xu, Jason Lupescu and Jeff Hepburn

 The vehicle tailpipe emissions based on current standards need to be reduced significantly to meet the future regulations, such as SULEV30 and SULEV20. The HC (Hydrocarbon) cold start emission remains as a major challenge for emission reduction and many efforts were put on this respect. One solution is to use the HC trap which includes Zeolite and TWC. Zeolite material captures the engine out HC at the very beginning of engine start and TWC material converts the adsorbed HC when catalyst is warmed up.

The challenge for this approach is that TWC needs a considerable high temperature (above 250°C) for HC light-off and zeolite normally releases most HC before TWC is hot enough to convert HC. This study shows that some transitional metals can improve the HC storage performance significantly. Cu, Ni and Mn were added to Beta Zeolite. The impacts of transitional metal to the adsorption and desorption to ethanol, propylene and toluene were studied. The results indicated Ni and Mn can benefit the E10 engine cold start and Cu can benefit the E85 engine cold start. The interaction of multiple metals was also studied and some configurations were introduced to avoid the negative interaction and enhance the overall performance.