Co Single Atoms and CoOx Nanoclusters Anchored on Ce0.75Zr0.25O2 Synergistically Boosts the NO Reduction by CO

Achieving high NO conversion and N-2 selectivity in selective catalytic reduction 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 is rationally developed with dual active centers consisting of both Co single-atoms (SAs) and CoOx nanoclusters (NCs) co-anchored on Ce0.75Zr0.25O2 support (CZO), which show above 99.7% NO conversion and 100% N-2 selectivity at 250-400 degrees C under 5 vol% O-2. DFT calculation and experimental results confirm a strong interaction among Co SAs, CoOx NCs, and CZO support. Co SAs enhance CO adsorption and accompany the oxygen vacancies (OVs) formation in CZO, while the CoOx NCs promote both NO conversion to nitrate intermediate and the breakage of the N-O bond at OVs, thus synergistically boosting the N-2 formation.