Co Single Atoms and CoO_x Nanoclusters Anchored on Ce_(0.75)Zr_(0.25)O_2 Synergistically Boosts the NO Reduction by CO

摘要

Achieving high NO conversion and N2 selectivity in selective catalyticreduction of NO by CO (CO-SCR) in a wide operating temperature window,particularly in the presence of high O_2 concentration, remains a big challenge.Herein, guided by density functional theory (DFT) calculations, a catalyst isrationally developed with dual active centers consisting of both Cosingle-atoms (SAs) and CoO_x nanoclusters (NCs) co-anchored onCe_(0.75)Zr_(0.25)O_2 support (CZO), which show above 99.7 NO conversion and100 N2 selectivity at 250–400 ℃ under 5 vol O_2. DFT calculation andexperimental results confirm a strong interaction among Co SAs, CoO_x NCs,and CZO support. Co SAs enhance CO adsorption and accompany the oxygenvacancies (OVs) formation in CZO, while the CoO_x NCs promote both NOconversion to nitrate intermediate and the breakage of the N–O bond at OVs,thus synergistically boosting the N_2 formation.