NO Heterogeneous Catalysis Viewed from the Angle of Nanoparticles

NO Heterogeneous Catalysis Viewed from the Angle of Nanoparticles 

Frederic Thibault-Starzyk, Marco Daturi, Philippe Bazin, and Olivier Marie 

Copyright 2008 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim 

we will first present briefly the general chemistry at work in deNOx catalysis. Then we wiU focus on the various specific nanometric issues in the domain. NOx decomposition mainly takes place on a metal center, as do most redox reactions in heterogeneous catalysis. We will therefore focus on how nanometric size influences the role of metal particles in this domain. It is very much linked to interaction with the oxide support, which wiU be the subject of the following part Zeolites are very specific oxide supports, controlling the distance between reactants and imposing chemical reactivity within the nanometer scale. Metal particles formed in zeoHtes have their size controlled between 0.5 and several dozens of nm, sometimes with Angstrom accuracy. We wiU next deal with three-way catalysts, mainly used for automotive deNOx. They involve very complex solids, where particle size is a key issue for activity. Finally, we wiU mention quickly new nanometric sohds like carbon nanotubes, which have appeared recently in deNOx catalysis. 

Using isotopically labelled reactants, it has been demonstrated that on both vanadia-based catalysts and noble metals, the two nitrogen atoms of N2 arise one from NO and the other from ammonia. V20s-based catalysts also catalyse the reduction of NO2 in the presence of oxygen  

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I 7(5 NO Heterogeneous Catalysis Viewed from the Angle of Nanoparticles... 

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