Advancing Ce–Cu–Al2O3 catalysts for waste-to-energy through strategic surface coordination modulation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 505; p. 159015
• Main Authors: Ahn, Seon-Yong, Oh, Min-Ju, Shim, Jae-Oh, Roh, Hyun-Seog
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2025
• Subjects: active Cu species; High-temperature water–gas shift; Precipitation sequence; Surface coordination structure; Waste-derived synthesis gas; Waste-derived synthesis gas; Surface coordination structure; active Cu species; Precipitation sequence; High-temperature water–gas shift
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.159015

[Display omitted] •Controlled precipitation sequence to adjust surface coordination.•Adjusting catalyst surface coordination enhances associative and redox mechanisms.•One-pot coprecipitated catalysts exhibited exceptional performance.•Stability of catalysts impacted by final precipitate via shielding effect. Here, by varying the precipitation sequence during the synthesis of Ce–Cu–Al2O3 catalysts, surface-exposed atoms were controlled to dramatically enhance the intrinsic activity and stability. The reaction results revealed that the number of active sites were crucial at low temperatures. At high temperatures, the oxygen storage capacity and surface concentration of Ce3+ and Cu+ became key, with Ce or Al exposure protecting active Cu species from sintering-induced deactivation. Characterization and catalytic reaction results confirmed the superior WGS performance of the one-pot coprecipitated Ce–Cu–Al2O3 catalyst, which features abundant active Cu species, providing adsorption sites for CO activation and a lower energy barrier for H2O dissociation (reaction rate: 76.35 μmolCOgcat−1s−1; turnover frequency: 0.694 s−1 at kinetic conditions). In addition, this catalyst exhibited high stability over 50 h, significantly outperforming the sequential impregnated Ce/Cu/Al2O3 catalyst, highlighting the importance of surface coordination structure in improving catalytic performance.