Metal–support interactions have a strong impact on the performance of heterogeneous catalysts. Specific sites at the metal–support interface can give rise to unusual high reactivity, and there is a growing interest in optimizing not only the properties of metal particles but also the metal–support interface. Here, we demonstrate how varying the particle size of the support (ceria–zirconia) can be used to tune the metal–support interactions, resulting in a substantially enhanced CO₂ hydrogenation rate. A combination of X-ray diffraction, X-ray absorption spectroscopy, near-ambient pressure X-ray photoelectron spectroscopy, transmission electron microscopy and infrared spectroscopy provides insight into the active sites at the interface between cobalt and ceria–zirconia involved in CO₂ hydrogenation to CH₄. Reverse oxygen spillover from the support during treatment in hydrogen results in the generation of oxygen vacancies. Stabilization of cobalt particles by ceria–zirconia particles of intermediate size leads to oxygen spillover to the support during the CO₂ and CO dissociation steps, followed by further hydrogenation of the resulting intermediates on cobalt.

金属与载体的相互作用对非均相催化剂的性能有很大影响。金属-载体界面上的特定位点会引起异常的高反应活性，并且人们不仅对金属颗粒的性能而且对金属-载体界面的优化也越来越感兴趣。在这里，我们演示了如何使用改变载体（氧化铈–氧化锆）的粒径来调整金属与载体之间的相互作用，从而显着提高CO _2的氢化率。X射线衍射，X射线吸收光谱，近环境压力X射线光电子光谱，透射电子显微镜和红外光谱的结合，提供了对涉及CO _2的钴与二氧化铈-氧化锆之间界面的活性位点的了解。氢化成CH ₄。在氢气处理过程中，从载体上逆向氧气溢出会导致氧气空位的产生。中等尺寸的氧化铈-氧化锆颗粒对钴颗粒的稳定作用会导致氧气在CO ₂和CO分解步骤中溢出到载体上，然后在钴上进一步氢化生成的中间体。