Lean-Burn Catalysts from the Perspective of a Car Manufacturer. Early Work at Volkswagen Research

Influence of Synthesis Conditions for ZSM-5 on the Hydrothermal Stability of Cu-ZSM-5

“…Close to 20 years ago, copper ion-exchanged zeolite ZSM-5 was shown to have high activity for NO x reduction under lean conditions [1,2]. A period of large efforts to understand the properties of this catalytic system followed, but the material was found to be insufficiently stable for automotive applications [3].…”

Engineering HC-SCR: Improved Low Temperature Performance through a Cascade Concept

“…On the other hand, such approach results in increased fuel penalty, as hydrogen should be produced onboard by fuel reforming. At the same time, Cu-zeolite has been reported to be active in HC-SCR at significantly lower temperatures than Ag/ alumina [9]. The drawback with zeolites is the dealumination of the structure in steam and at elevated temperatures.…”

SERS and infrared reflection‐absorption spectroscopy of NO on cold‐deposited Cu

“…Copper and Cu-Cr on an alumina monolith have been investigated as an alternative to the Pt/Rh (5 : 1) three-way (conversion of CO, CH x and NO) catalyst with promising results. 17 Modern lean-burn engines prohibit the use of the three-way catalyst, 18 and therefore, Cu : zeolite catalysts are under consideration. 19 -21 SERS by partially reduced Ag powder in a He gas stream, to which a pulse of NO was added, yielded 22 only the vibrational bands of NO 2 .…”