Deactivation of Cu/SAPO-34 during low-temperature NH3-SCR

Artikel i vetenskaplig tidskrift, 2015

The sensitivity of NH3-SCR activity to water vapour at 70 degrees C is tested for Cu/SAPO-34 (morph.) catalysts. The synthesised Cu/SAPO-34 (morph.) is remarkably susceptible to low-temperature activity loss. After only 3 hat 70 degrees C, the NOx conversion decreases from an initial 87% to 66% at 200 degrees C, after another 9 h to 6%. This deactivation is accompanied by a partial loss of microporous volume, but the SAPO-34 framework remains crystalline. We postulate that a transformation of the active copper sites into an inactive form could be the cause for the deactivation. Regeneration of the catalyst was attempted, but had no impact on activity.