Inorganic Chemistry and Catalysis Group, Institute for Sustainable and Circular Chemistry and Debye Institute for Nanomaterials Science, Utrecht University, 3584 CG Utrecht, Netherlands.
EMAT and NANOlab Center of Excellence, University of Antwerp, 2020 Antwerp, Belgium.
Science. 2023 May 12;380(6645):644-651. doi: 10.1126/science.adf6984. Epub 2023 May 11.
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 TiO overlayers formed on nickel/titanium dioxide catalysts during 400°C reduction were completely removed under carbon dioxide hydrogenation conditions. Conversely, after 600°C reduction, exposure to carbon dioxide hydrogenation reaction conditions led to only partial reexposure of nickel, forming interfacial sites in contact with TiO 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.
可还原载体通过还原过程中形成亚氧化物覆盖层来影响金属催化剂的性能，这一过程被称为强金属-载体相互作用（SMSI）。原位电子显微镜和振动光谱的组合表明，在 400°C 还原过程中，在镍/二氧化钛催化剂上形成的薄 TiO 覆盖层在二氧化碳加氢条件下完全去除。相反，在 600°C 还原后，暴露于二氧化碳加氢反应条件下仅导致镍的部分重新暴露，在与 TiO 接触的界面处形成位，并通过提供碳物种库来促进碳-碳偶联。我们的发现挑战了对 SMSI 的传统理解，并呼吁在单颗粒水平上对纳米催化剂进行更详细的原位研究，以重新审视结构-活性关系的静态模型。
