Synergic Effect of ferrierite exchanges Co and Pt for the CH4-SCR of NOx

BOIX, ALICIA; ASPROMONTE, SOLEDAD; LOMBARDO, EDUARDO; MIRÓ, EDUARDO

Río de Janeiro, Brasil

Congreso; 2nd Mercosur Congress on Chemical Engineering, 4th Mercosur Congress on Process Systems Engineering; 2005

ABEQ - Associaçao Brasileira de Engenharia Química

The selective catalytic reduction of NOx with hydrocarbons and particularly with methane is one of the most studied pathways to abate emissions of these oxides in flue gas from stationary sources . Particularly, we found that PtCo zeolites are very active and selective catalysts for N2 production. They are more selective than Co zeolites and show an enhanced water resistance. We suggested a synergistic effect between the metals. CoFER and PtCoFER were prepared with different Co loadings and Co/Pt ratios. In order to use the PtCo system in combustion exhausts, the powder material has to be washcoated on cordierite monoliths. To increase adherence, silica was added to the slurry as a binder. The samples were assayed for the SCR of NOx with methane in excess oxygen. The maximum conversion of NOx to N2 went through a maximum with the Co loading and the Co/Pt ratio. All the catalysts partially deactivated with 2% water. A thorough TPR, XPS and LRS characterization of fresh and deactivated catalysts showed that two deactivation mechanisms are operative. At low Co loading, the formation of Pt clusters is responsible for the low selectivity, while for higher loadings Co3O4 is formed and is the non-selective species. Keywords: CoPtFerrierite, Cordierite Monoliths, NOx Reduction, Deactivation