Insight of platinum poisoning Cu/SAPO-34 during NH3-SCR and its promotion on catalysts regeneration after hydrothermal treatment

Abstract This study mainly focused on selective catalytic reduction of air pollutants NO x by ammonia (NH 3 -SCR), and a series of Pt impregnated Cu/SAPO-34 (homemade) samples were employed to elucidate its negative impact on DeNO x activity and hydrothermal treatment’s acceleration on NH 3 -SCR activity resurgence. Firstly, XRD, NH 3 -TPD and DRIFTs were performed to examine platinum interaction with zeolites structure and contribution to acidity. Then, Pt inhibition on NH 3 -SCR activity was evaluated and its impact on reaction network, including ammonia oxidation, NO oxidation and NO + NH 3 , was concluded based on gas switching tests. H 2 -TPR and EPR further reflected various Cu species coordination and redox capacity variation caused by platinum doping. It was intriguing to find out that the further hydrothermal treatment benefited rejuvenation of Pt-poisoned Cu/SAPO-34 and even activity enhancement from Pt presence under the condition of zeolites structure integrity. Hydrothermal treatment induced platinum sintering and STEM illustrated platinum species combined with copper oxides and generated oxo-complexes, weakening ammonia oxidation. And Pt presence promoted copper oxides further dispersion during hydrothermal treatment. Finally, platinum poisoning on Cu/SAPO-34 and its regeneration after hydrothermal treatment were concluded to indicate their application potential.