The active sites of a Cu-zeolite catalyst for diesel emissions control are not static, but are created and dissolved on the fly as the reaction proceeds.
This concept of dynamic active sites is new to heterogeneous catalysis and provides new and exciting insights in the function of Cu-zeolites in the selective catalytic reduction of NOx by ammonia (NH3-SCR) in diesel exhaust gases. The key feature is that mobile Cu(NH3)2+ complexes form pairs that are able to dissociate oxygen molecules. This knowledge helps to develop materials for better and more robust catalyst materials to eliminate smog formation and improve air quality around the globe.
The new knowledge is presented in the latest issue of Science by Paolucci et al. from Notre Dame University, Purdue University, and Cummins Inc. (C. Paolucci et al., Science 357 (2017) 898). Haldor Topsoe’s Ton V.W. Janssens and Peter N.R. Vennestrøm (Science 357 (2017) 866) have written a Perspective commentary to the article, that you can access for free here:
NOx are nitrogen oxides that contribute to the formation of smog and acid rain. They are formed by combustion of fuels in engines, power plants, and industry.