Development of Advanced Durable Lean NOx Catalysts for Diesel Engine Aftertreatment
EMSL Project ID
1650
Abstract
Although substantial effort has been devoted to understand and improve lean NOx catalysts, there is no known catalyst that meets the requirements necessary for commercial applications...Llittle effort has been devoted to systematically investigating the relationship between the surface structure of active metal oxides on alumina support and its catalytic activity... It is the objective of the proposed research to investigate the nature of the active sites of promising metal oxide materials so that the catalytic performance can be improved further through a proper design of catalyst preparation processes or an addition of necessary catalytic promoters. Catalytic NOx reduction is a complex process that should be studied at the molecular level utilizing a unique combination of expertise, instrumental techniques and novel insight into catalyst chemistry. XPS, XRD and TEM will be used to determine the effect of metal loading on the chemical state and dispersion of metal oxide phases supported on alumina. The information derived from these techniques will be correlated with probe reaction such as NOx reduction or hydrocarbon combustion to develop a more complete understanding of alumina supported metal oxide catalysts. These measurements will provide direct information on the chemical and phsical properties of the active sites (metal oxides) such as crystallinity, dispersion, oxidation state, and morphology of the active component. In addition..., the durability of the promising catalyst candidates will also be studied. Aging tests will be conducted in simulated diesel exhaust conditions. Hydrothermal stability (sintering), carbon deposition (coking) and SO2 tolerance (poisoning) will be examined. The combination of these chacterization techniques will be used to assess changes in the catalyst surface structure and their effect on deNOx performance in order to gain an insight into catalyst deactivation mechanisms.
Project Details
Project type
Exploratory Research
Start Date
1999-08-31
End Date
2002-08-28
Status
Closed
Released Data Link
Team
Principal Investigator