Unravelling the phosphorus-induced effect on NH3-SCR catalytic performance, hydrothermal stability and SO2 resistance of Cu/SAPO-34

Abstract

The current work focused on the effect of PO43- on the hydrothermal stability and SO2 resistance of Cu/SAPO-34. The activity results showed that the addition of phosphorus promoted the low-temperature SCR reaction of fresh Cu/SAPO-34. H2-TPR revealed that the addition of P induced more Cu2+-2Z species in Cu/SAPO-34, and all of Cu2+-2Z species were well preserved after hydrothermal aging at 800 °C, contributing to the low-temperature SCR activity. Moreover, the addition of an appropriate amount of external P source can effectively inhibit the adsorption of SO2 on the Cu/SAPO-34 and block the binding of SO2 to active Cu2+ sites owing to the reduced [Cu(OH)]+-Z species, thereby improving the anti-SO2 poisoning ability of Cu/SAPO-34. In situ DRIFTS results demonstrated that the SCR reaction with or without SO2 over Cu/SAPO-34 and P-doped Cu/SAPO-34 took place concurrently through the E-R and L-H mechanism.