Interface‐Controlled Synthesis of Single‐Ce and CeOx Catalysts on Copper Oxide Surfaces

Abstract The rational design of single‐atom cerium (single‐Ce) catalysts on copper oxides is crucial for understanding structure–activity relationships in Ce‐Cu oxide systems. Using scanning tunnelling microscopy (STM) and X‐ray photoelectron spectroscopy (XPS), we systematically investigated Ce atom deposition on Cu(111) and Cu 2 O surfaces under controlled oxygen atmospheres, revealing distinct interfacial behaviors. On Cu(111), Ce atoms readily aggregate into clusters due to weak metal‐substrate interactions. In contrast, Cu 2 O surfaces stabilize single Ce atoms through strong Ce‐O bonding, enabling atomic dispersion at 300 K. By controlling surface structure and Ce coverage, we synthesized stable single‐Ce catalysts on three distinct Cu 2 O phases: the metastable “5–7” and ordered “44” and “29” superstructures. Thermal annealing studies (480–550 K) demonstrated that single‐Ce and CeO x clusters can dissociate O 2 and promote Cu 2 O oxidation, forming a copper oxide phase with ribbon‐like structures. XPS analysis showed a decrease in Ce 3+ concentration upon annealing, correlating with enhanced oxygen activation. These findings establish Cu 2 O as a platform for synthesizing and stabilizing single‐Ce catalysts, providing mechanistic insights for further catalytic applications.