Browse Publications Technical Papers 2014-01-1515

DOC Development Targeting Emerging High S Area Market 2014-01-1515

Low cost and S(sulphur)-tolerant DOCs (Diesel Oxidation Catalysts) are being demanded in emerging countries such as China and India, where Euro 4 and 5 type emission standards are going to be implemented or are being implemented. However, fuel S content is different in the metros vis-à-vis non metros in many emerging countries. In such a scenario, DOCs need to maintain catalytic performance with high S fuel as well as standard low S fuel. This paper describes the development results of S tolerant Pt-Pd based DOCs.
A new washcoat technology (WT D) has been developed for EU 4 passive Pt-Pd DOC applications, in which PGM cost was thrifted by replacing part of Pt by Pd. Vehicle test results after thermal ageing and S poisoning demonstrated that the Pt-Pd DOC (Pt:Pd=4:1) prepared with WT D gave similar tailpipe CO (Carbon monoxide) and HC (Hydrocarbon) emission conversions as a commercially available EU 4 passive Pt-only DOC when 50ppm S diesel fuel was used. When 350ppm S fuel was used, the Pt-Pd DOC exhibits higher CO and THC emission conversions than the Pt DOC.
For EU 5 pre-DPF (Diesel Particulate Filter) DOC, a new washcoat technology (WT E) has been proposed. Engine bench test results show the DOC prepared with WT E has higher CO and HC oxidation activity than a commercially available EU 5 Pt-Pd DOC (WT B) after S poisoning and 40∼50% PGM cost can be thrifted. Moreover, fuel combustion performance for downstream CSF (catalyzed soot filter) at forced regeneration has been proven, even with 500 ppm S fuel.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 16% off list price.
Login to see discount.
We also recommend:

Emission Characteristics from After-Treatment System of Medium and Light Duty Engines


View Details


Cause and Effect of Reversible Deactivation of Diesel Oxidation Catalysts


View Details


Possible Exhaust Gas Aftertreatment Concepts for Passenger Car Diesel Engines with Sulphur-free Fuel


View Details