The catalytic efficiency of CeO₂ in soot oxidation was significantly affected by its grain morphology and calcination temperature. Nanocube-shaped and nanorod-shaped CeO₂ catalysts were synthesized via a hydrothermal method with different calcination temperatures. Activity tests revealed that the nanorod-shaped CeO₂ exhibited superior catalytic activity compared to the nanocube-shaped catalysts at equivalent calcination temperatures. Furthermore, an inverse relationship between the catalytic activity and the calcination temperature was observed in the nanorod-shaped CeO₂ catalysts, with those calcined at 300 °C exhibiting the most effective low-temperature catalytic performance. Combined characterization techniques and density functional theory calculations showed that the improved catalytic performance can be attributed to the increased abundance of oxygen vacancies, enhanced lattice oxygen mobility and higher surface energy due to their unique surface defect structure and electronic structural feature, in addition to the reduction in grain size.

中文翻译：

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煅烧温度对 CeO2 烟灰氧化催化活性的影响：实验与理论相结合的方法


CeO ₂ 对烟灰氧化的催化效率受其晶粒形貌和焙烧温度的影响显着。采用水热法在不同的焙烧温度下合成了纳米立方体和纳米棒状CeO ₂ 催化剂。活性测试表明，在同等焙烧温度下，纳米棒状CeO ₂ 与纳米立方体催化剂相比表现出优异的催化活性。此外，纳米棒状CeO ₂ 催化剂的催化活性与煅烧温度之间存在反比关系，其中在300℃下煅烧的催化剂表现出最有效的低温催化性能。结合表征技术和密度泛函理论计算表明，催化性能的提高可归因于氧空位丰度的增加、晶格氧迁移率的增强以及由于其独特的表面缺陷结构和电子结构特征而产生的更高的表面能，此外还归因于还原在粒度上。