Chemical kinetics affords insights into chemical reactions by directly informing on intermediates along the reaction pathway. Chemical kinetics also informs process designers to conceive and optimize new chemical processes. These principles are discussed in two examples relevant to automotive catalysis and Prof. Iglesia’s seminal contributions. The first example involves NOx trapping to control emissions from diesel engines. NOx traps employ a catalyst, such as Pt, and a sorbent, such as BaO. Chemical kinetics studies revealed unexpected synergies between the catalyst and storage functions. NOx is sorbed more effectively as NO2, instead of NO which is the main species in exhaust. Pt provides the necessary NO oxidation function but is also poisoned by the resulting NO2. Sorption of NO2 by BaO maintains low NO2 concentration and relieves inhibition of Pt, resulting in more effective Pt use. A further synergy arises because NOx trapping requires an additional oxidation of NO2 to NO3- (nitrate). Here, the Pt catalyst provides another intermediate that assists this oxidation on BaO much faster than gas phase NO2. These synergies result in a more effective trapping system than is achieved with the Pt and BaO components in isolation. The second example involves steam reforming of gasoline to H2 and CH4 on a vehicle to provide a higher octane, faster burning mixture for the engine. Rh catalysts on large pore supports favor gasoline conversion to CO and H2, with little CH4 formation. A chemical kinetics study revealed that CH4 formation is inhibited by carbon deposits from higher hydrocarbons. As a result, Rh catalysts encapsulated in small pore zeolites were developed to exclude hydrocarbons and yield more CH4. The formation of CH4 provides heat for the endothermic reforming reactions and also relieve CO inhibition of the reforming catalyst. As a result, the dual-catalyst system enables much higher fuel conversion.

From chemical kinetics to chemical processes in automotive catalysis

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.