Atomic-level engineering of single Ag site distribution on titanium-oxo cluster surfaces to boost CO electroreduction

• Published in: Chemical science (Cambridge) Vol. 16; no. 16; pp. 6845 - 6852
• Main Authors: Meng, Ru-Xin, Zhao, Lan-Cheng, Luo, Li-Pan, Tian, Yi-Qi, Shao, Yong-Liang, Tang, Qing, Wang, Likai, Yan, Jun, Liu, Chao
• Format: Journal Article
• Published: 16.04.2025
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d4sc07186g

Precise control over the distribution of active metal sites on catalyst surfaces is essential for maximizing catalytic efficiency. Addressing the limitations of traditional cluster catalysts with core-embedded catalytic sites, this work presents a strategy to position catalytic sites on the surfaces of oxide clusters. We utilize a calixarene-stabilized titanium-oxo cluster ( Ti 12 L 6 ) as a scaffold to anchor Ag 1+ in situ , forming the unique nanocluster Ti 12 Ag 4.5 with six surface-exposed Ag 1+ sites. The in situ transformation from Ti 12 L 6 into Ti 12 Ag 4.5 clusters was traced through mass spectrometry, revealing a solvent-mediated dynamic process of disintegration and reassembly of the Ti 12 L 6 macrocycle. The unique Ti 12 Ag 4.5 cluster, featuring a surface-exposed catalytic site configuration, efficiently catalyzes the electroreduction of CO 2 to CO over a broad potential window, achieving CO faradaic efficiencies exceeding 82.0% between −0.4 V and −1.8 V. Its catalytic performance surpasses that of bimetallic Ti 2 Ag 2 , which features a more conventional design with Ag 1+ sites embedded within the cluster. Theoretical calculations indicate that the synergy between the titanium-oxo support and the single Ag 1+ sites lowers the activation energy, facilitating the formation of the *COOH intermediate. This work reveals that engineered interactions between active surface metal and the oxide support could amplify catalytic activity, potentially defining a new paradigm in catalyst design. We present an approach designed to strategically position Ag 1+ sites on the surfaces of oxide clusters. The resulting cluster demonstrates exceptional catalytic activity, with the exposed Ag sites efficiently electrochemically reducing CO 2 to CO.