Identification of the mechanism of NO reduction with ammonia (SCR) on zeolite catalysts.

ABSTRACT: Cu/zeolites efficiently catalyze selective reduction of environmentally harmful nitric oxide with ammonia. Despite over a decade of research, the exact NO reduction steps remain unknown. Herein, using a combined spectroscopic, catalytic and DFT approach, we show that nitrosyl ions (NO⁺) in zeolitic micropores are the key intermediates for NO reduction. Remarkably, they react with ammonia even below room temperature producing molecular nitrogen (the reaction central to turning the NO pollutant to benign nitrogen) through the intermediacy of the diazo N₂H⁺ cation. Experiments with isotopically labeled N-compounds confirm our proposed reaction path. No copper is required for N₂ formation to occur during this step. However, at temperatures below 100

SUBMITTER: Khivantsev K 

PROVIDER: S-EPMC9475367 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature