Modulating active sites: A-site doped ACu-CeO2 catalyst for efficient CO-SCR of NO

Abstract

Transition metal-based nanomaterials have gained significant attention as highly active and cost-effective catalysts for the selective catalytic reduction (SCR) of NO with CO. Using a simple wet impregnation method, the catalyst composition and active sites can be modulated. In this paper, we present a novel cerium-based co-solvent catalyst, A-site doped ACu-CeO2 (A = Co, Fe, Mn), for CO-SCR of NO. The doping of A-site elements induces structural changes and enhances catalytic performance. Among the doped catalysts, CoCu-CeO2 exhibits a wide temperature window for operation and high selectivity towards nitrogen, achieving 100% NO conversion at 200 °C. Furthermore, A-site modulation not only promotes electron/ion transfer within the catalyst but also enables uniform and dispersed distribution of the active metal species, particularly copper, in the CoCu-CeO2 catalyst. This provides reaction centers for the selective reduction of NO by CO and enhances the adsorption capacity of the catalyst for NO. The ACu-CeO2 catalyst demonstrates excellent CO-SCR catalytic performance and resistance to vapor. Characterization techniques such as XPS, Raman spectroscopy, and in situ DRIFTS elucidate the reaction mechanism of the ACu-CeO2 cerium-based co-solvate in the CO-SCR reaction. This study furthers our understanding and improvement of catalyst design, while also providing an efficient and straightforward denitrification catalyst for controlling air pollutants.