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CAER Seminars

Low Temperature NOx Adsorbers for Cold-Start NOx Control on Diesel Engines

Joseph R. Theis
Ford Motor Company’s Research and Innovation Center

April 29, 2015 at 10:00am
Ben Bandy Conference Center
UK Center for Applied Energy Research


It is well known that selective catalytic reduction (SCR) with urea injection is highly effective for NOx control on diesel engines once the SCR catalyst has warmed up to ca. 200oC. However, even with rapid heat-up strategies that consume extra fuel, slow warmup rates on diesels require that the urea injection be delayed for up to 200 seconds following a cold-start, resulting in high NOx emissions during the cold-start period. Low temperature NOx adsorbers (LTNA) are being developed that can store the NOx during a cold start and then release it at higher temperatures once the SCR system has become operational. This seminar will focus on our assessment of LTNAs for cold-start NOx control at the Ford Research Labs. Several model catalysts involving Pt or Pd on washcoats of alumina or ceria/zirconia were assessed for their ability to store NOx during the cold start period and then release the stored NOx once the exhaust system has warmed up. The effects of other exhaust species such as H2O, HC, and CO on the NOx storage performance will be discussed. The effect of the catalyst pretreatment on the storage performance will also be investigated. The talk will conclude with some early DRIFTS work that is intended to explore the interactions between the various exhaust species on the surface of the catalyst.