Restructuring of titanium oxide overlayers over nickel nanoparticles during catalysis

• 成果类型: Article
• 署名作者: Monai, Matteo; Jenkinson, Kellie; Melcherts, Angela E. M.; Louwen, Jaap N.; Irmak, Ece A.; Van Aert, Sandra; Altantzis, Thomas; Vogt, Charlotte; van der Stam, Ward; Duchon, Tomas; Smid, Bretislav; Groeneveld, Esther; Berben, Peter; Bals, Sara; Weckhuysen, Bert M.
• 署名单位: Utrecht University; Utrecht University; University of Antwerp; University of Antwerp; Helmholtz Association; Research Center Julich; Charles University Prague; Technion Israel Institute of Technology
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9052
• DOI: 10.1126/science.adf6984
• 发表日期: 2023-05-11
• 页码: 644-651
• 关键词: metal-support interactions; co2 hydrogenation; sites

摘要

Reducible supports can affect the performance of metal catalysts by the formation of suboxide overlayers upon reduction, a process referred to as the strong metal-support interaction (SMSI). A combination of operando electron microscopy and vibrational spectroscopy revealed that thin TiOx overlayers formed on nickel/titanium dioxide catalysts during 400 degrees C reduction were completely removed under carbon dioxide hydrogenation conditions. Conversely, after 600 degrees C reduction, exposure to carbon dioxide hydrogenation reaction conditions led to only partial reexposure of nickel, forming interfacial sites in contact with TiOx and favoring carbon-carbon coupling by providing a carbon species reservoir. Our findings challenge the conventional understanding of SMSIs and call for more-detailed operando investigations of nanocatalysts at the single-particle level to revisit static models of structure-activity relationships.