Modulating Nanoparticle Structure by Metal–Metal Oxide Interfacial Interaction in a CeO2‑Supported Bimetallic System: The Ni–Cu Case

• Published in: The journal of physical chemistry letters Vol. 15; no. 15; pp. 4096 - 4104
• Main Authors: Tu, Yi, Huang, Luchao, Cheng, Xingwang, Tian, Bingchu, Zhang, Dongling, Hu, Jun, Ding, Honghe, Xu, Qian, Ye, Yifan, Zhu, Junfa
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.04.2024
• Subjects: Physical Insights into Chemistry, Catalysis, and Interfaces
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.4c00810

Structure-optimized bimetallic and multicomponent catalysts often outperform single-component catalysts, inspiring a detailed investigation of metal–metal and metal–support interactions in the system. We investigated the geometric and electronic structures of ceria-supported Ni–Cu particles prepared using different metal deposition sequences employing a combination of X-ray photoelectron spectroscopy, resonant photoemission spectroscopy, and infrared reflection absorption spectroscopy. The bimetallic model catalyst structure was altered by a distinct surface evolution process determined by the metal deposition sequence. The postdeposited Cu stays on the surface of Ni predeposited CeO2 and forms only a limited Ni–Cu alloy in the Cu-contacted Ni region. However, when Ni is deposited on the Cu predeposited CeO2 surface, Ni can migrate through the Cu layer to the Cu–ceria interface and form an extended Ni–Cu alloy to the whole deposited metal layer on the ceria surface. The dynamic metal diffusion in the CeO2-supported Ni–Cu system indicates that metal–support interactions can be used to achieve the rational design of a bimetallic composition distribution during catalyst preparation.