Pt-based catalysts are widely used in catalytic combustion of hydrocarbons and play an important role in emission control. However, developing a Pt catalyst for efficient conversion of hydrocarbons at low temperatures remains challenging. Herein, the structure–performance relationship between Pt size and C₃H₈ oxidation activity was studied over Pt–CeO₂ catalysts. The samples with different Pt initial states of single atoms and nanoparticles were obtained by different reduction treatments. No obvious differences were found between the two catalysts in the performances of C₃H₈ oxidation. The Pt states were found to be dynamically changing during C₃H₈ oxidation, and the evolution behaviors were closely related to the Pt initial states; Pt single atoms continuously sintered into clusters and then transformed into Pt nanoparticles with elevated reaction temperatures, while initial Pt nanoparticles firstly dispersed into small clusters and then re-sintered into nanoparticles. It is concluded that the different adsorption properties of C₃H₈ and O₂ on Pt species with different sizes are responsible for their different evolution behaviors during C₃H₈ oxidation based on DFT analyses.

中文翻译：

---

Pt-CeO2 催化剂上丙烷氧化过程中不同初始尺寸 Pt 的演化


铂基催化剂广泛应用于碳氢化合物的催化燃烧，在排放控制中发挥着重要作用。然而，开发一种在低温下有效转化碳氢化合物的铂催化剂仍然具有挑战性。在此，研究了Pt-CeO ₂催化剂上Pt尺寸和C ₃ H ₈氧化活性之间的结构-性能关系。通过不同的还原处理得到不同Pt初始态的单原子和纳米粒子样品。两种催化剂的C ₃ H ₈氧化性能没有发现明显差异。发现C ₃ H ₈氧化过程中Pt态发生动态变化，其演化行为与Pt初始态密切相关；随着反应温度升高，Pt单原子不断烧结成簇，然后转变为Pt纳米颗粒，而初始Pt纳米颗粒首先分散成小簇，然后重新烧结成纳米颗粒。根据DFT分析得出结论，C ₃ H ₈和O ₂对不同尺寸的Pt物种的不同吸附特性导致了它们在C ₃ H ₈氧化过程中不同的演化行为。