Modulating CO2 methanation activity on Ni/CeO2 catalysts by tuning ceria facet-induced metal-support interaction

• Published in: International journal of hydrogen energy 2024-01, Vol.51, p.462-475
• Main Authors: Lin, Shuangxi, Tang, Rui, Liu, Xudong, Gong, Longchen, Li, Zhenhua
• Format: Article
• Language: English
• Subjects: CO2 methanation; Facets; Metal-support interactions; Ni/CeO2; Oxygen vacancies
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.10.095

Comprehending the metal-support interactions (MSI) as well as interface structures plays a crucial role in creating efficient interface sites. However, the interfacial nature is influenced by multiple structural factors, making it challenging to establish a direct correlation between interfacial sites and CO2 methanation activity. Herein, the CeO2 with uniform facets were used as supports to study the influence of facet-induced MSI on methanation performance. CeO2 cubes with (1 0 0) facet and octahedrons with (1 1 1) facet was fabricated over Ni/CeO2 by altering hydrothermal parameters. (HR)TEM, XPS and Raman characterizations etc. revealed that the presence of embedded MSI structures in Ni/CeO2-Cub resulted in the well-dispersed Ni0. The embedded Ni–CeO2 interaction owned a maximized interface with more surface oxygen vacancies. The FT-IR spectrum indicated that the synergistic effect of H2 dissociation on Ni NPs surfaces and CO2 activation in adjacent surface oxygen vacancies occurred in Ni–CeO2 interfaces, improving CO2 methanation activity with a large number of formates. CO2 conversion rate for Ni/CeO2-Cub was 18.4 times as high as that for Ni/SiO2 without MSI at 548 K. This study elucidated how the facet-induced interfaces impacted the methanation activity, providing new ideas for the development of efficient CO2 hydrogenation catalysts. [Display omitted] •The metal-support interaction was modulated by different CeO2 facets.•More surface oxygen vacancies were created at the embedded Ni–CeO2 interface.•The formate and adsorbed CO were identified as key intermediates.•The relationship between Ni–CeO2 interfaces and methanation activity was explored.