Strikingly distinctive NH₃-SCR behavior over Cu-SSZ-13 in the presence of NO₂.

ABSTRACT: Commercial Cu-exchanged small-pore SSZ-13 (Cu-SSZ-13) zeolite catalysts are highly active for the standard selective catalytic reduction (SCR) of NO with NH₃. However, their activity is unexpectedly inhibited in the presence of NO₂ at low temperatures. This is strikingly distinct from the NO₂-accelerated NO_x conversion over other typical SCR catalyst systems. Here, we combine kinetic experiments, in situ X-ray absorption spectroscopy, and density functional theory (DFT) calculations to obtain direct evidence that under reaction conditions, strong oxidation by NO₂ forces Cu ions to exist mainly as Cu^II species (fw-Cu²⁺ and NH₃-solvated Cu^II with high CNs), which impedes the mobility of Cu spec

SUBMITTER: Shan Y 

PROVIDER: S-EPMC9360435 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature