Role of the different copper species on the activity of Cu/zeolite catalysts for SCR of NOx with NH3

- NH3 NOx-SCR is studied on Cu-ZSM5 and Cu-BETA prepared by ion exchange and impregnation.
- CuO and Cu(II) exchanged on tetrahedral and octahedral positions of zeolite framework were found.
- CuO prevails in high Cu-content on ZSM5. Isolated Cu(II) ions prevail in low Cu-content on BETA catalysts.
- CuO promotes NOx reduction at low temperature.
- Isolated Cu(II) ions maintain high NOx conversion at high temperatures.