Selective catalytic reduction of NOx by ammonia: adsorption of NO on Cu-SSZ-13 using Ab initio simulations

The goal of the selective catalytic reduction is to limit the emission of nitroxides (NOx) originating from combustion processes. Due to the upcoming tightening of the European legislation concerning emission from mobile sources, the importance of this process is rapidly increasing. In this process, fume gasses enriched with ammonia or urea, are brought into contact with a catalyst, effectively converting NOx into harmless gasses, i.e. nitrogen and water. Recently, experiments indicated that metal exchanged zeolites are particularly suited for this job, due to their high selectivity and hydrothermal stability [1]. This is especially true for copper-exchanged zeolites with a chabazite topology,i.e. CuSSZ-13, due to the relatively small pores. Moreover, the (almost) unique location of the active site (Cu 2+ ion), makes this particular catalyst very interesting from a research point of view [1,2].