Interplay between copper redox and transfer and support acidity and topology in low temperature NH₃-SCR.

ABSTRACT: Low-temperature standard NH₃-SCR over copper-exchanged zeolite catalysts occurs on NH₃-solvated Cu-ion active sites in a quasi-homogeneous manner. As key kinetically relevant reaction steps, the reaction intermediate Cu^II(NH₃)₄ ion hydrolyzes to Cu^II(OH)(NH₃)₃ ion to gain redox activity. The Cu^II(OH)(NH₃)₃ ion also transfers between neighboring zeolite cages to form highly reactive reaction intermediates. Via operando electron paramagnetic resonance spectroscopy and SCR kinetic measurements and density functional theory calculations, we demonstrate here that such kinetically relevant steps become energetically more difficult with lower support Brønsted acid strength and

SUBMITTER: Wu Y 

PROVIDER: S-EPMC10164144 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature