In the United States, catalysis is an essential technology not only for the production of most chemicals, but also for the treatment of waste and exhaust emissions. 

Sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain.

Nitrogen oxides (NO, NO2, N2O) contribute to several environmental hazards including global warming, smog, ground level ozone formation, and acid rain. NOx is primarily produced during the high temperature combustion of fossil fuels. Reciprocating engines, both mobile and stationary, are contributors to NOx emissions. Emission reduction is possible through modification of combustion parameters, but reducing NOx emissions to acceptable levels will require an effective aftertreatment technology. Current catalytic NOx reduction control technologies include three-way catalysts and ammonia-based selective catalytic reduction. While these methods are highly effective for current combustion technologies, they are unsuitable for the next generation of high efficiency lean-burn engines.

Present work is devoted to the development of a novel two-stage NOx reduction system. The system will first oxidize NO to NO2, and in a second stage perform the hydrocarbon reduction of NO2. NO2 is a more easily reduced species than NO, and thus should be better able to compete with the combustion reaction for hydrocarbon. Furthermore, as NO oxidation is a thermodynamically limited reaction at high temperatures, high excess oxygen will be a benefit to the performance of the system.

NO oxidation to NO₂ over supported cobalt catalysts.  (1000ppm NO, 10%O₂, balance He)