Engineering the surface structure of ceria-based catalysts at the atomic scale is a powerful strategy for boosting catalytic performance. Here, we carried out density functional theory calculations to investigate structure-activity relationships of Au-CeO₂ catalysts with (111), (110), and (100) surfaces exposed in common CeO₂ nanopolyhedra, nanorods and nanocubes, respectively. On stoichiometric AuCe_1-xO₂(111), (110) and (100) catalyst surfaces, HCHO oxidation follows the Mars van Krevelen mechanism. Calculations show that the migration of Au atoms on the surface of AuCe_1-xO₂(110) leads to a more stable configuration and improved HCHO oxidation performance than the undistorted (110) surface. On defective AuCe_1-xO₂(110) and (100) surfaces, HCHO oxidation follows the co-action of the Langmuir-Hinshelwood and Mars van Krevelen mechanisms with HCHO and O₂ co-participation and surface reduction by the removal of lattice oxygen. Adsorbed O₂ species contribute to a decrease in the energy barriers of the reaction steps. With the easy reducibility and lower energy barriers, the defect surfaces are more conducive to HCHO oxidation than stoichiometric surfaces. Whether stoichiometric surfaces or defective surfaces, (110) is most active for HCHO oxidation with the lowest activation energy for the rate-determining step, followed by (111), and then (100). Microkinetic simulations offer additional support for this result. Dopant Au atoms activate surface oxygen, and decrease the formation energy of oxygen vacancies. Au also reduces the energy barriers of key reaction steps on AuCe_1-xO₂(111) (110) (100) surfaces as compared to the pristine ceria surfaces. These calculations provide insight into the interaction between Au and CeO₂ with different surface terminations and the effect of the CeO₂ crystal plane and their reactivity for HCHO catalytic oxidation.

在原子尺度上设计氧化铈基催化剂的表面结构是提高催化性能的有力策略。在这里，我们进行了密度泛函理论计算，以研究 Au-CeO ₂催化剂与暴露在常见 CeO ₂纳米多面体、纳米棒和纳米立方体中的（111）、（110）和（100）表面的构效关系。在化学计量的 AuCe _1-x O ₂ (111)、(110) 和 (100) 催化剂表面上，HCHO 氧化遵循 Mars van Krevelen 机制。计算表明Au原子在AuCe _1-x O ₂表面的迁移(110) 导致比未变形的 (110) 表面更稳定的构型和改进的 HCHO 氧化性能。在有缺陷的 AuCe _1-x O ₂ (110) 和 (100) 表面上，HCHO 氧化遵循 Langmuir-Hinshelwood 和 Mars van Krevelen 机制的共同作用，HCHO 和 O ₂共同参与并通过去除晶格进行表面还原氧。吸附O ₂物种有助于降低反应步骤的能垒。由于易于还原和较低的能垒，缺陷表面比化学计量表面更有利于 HCHO 氧化。无论是化学计量表面还是有缺陷的表面，(110) 对 HCHO 氧化最活跃，速率决定步骤的活化能最低，其次是 (111)，然后是 (100)。微动力学模拟为这一结果提供了额外的支持。掺杂金原子活化表面氧，并降低氧空位的形成能。与原始氧化铈表面相比，Au 还降低了 AuCe _1-x O ₂ (111) (110) (100) 表面上关键反应步骤的能垒。这些计算提供了对 Au 和 CeO 之间相互作用的深入了解_{图 2}具有不同的表面终止和 CeO ₂晶面的影响及其对 HCHO 催化氧化的反应性。