Understanding of Au-CeO2 interface and its role in catalytic oxidation of formaldehyde
Understanding of Au-CeO2 interface and its role in catalytic oxidation of formaldehyde
复制标题
Au-CeO2界面及其在甲醛催化氧化中的作用的认识
DOI：
10.1016/j.apcatb.2019.118138
复制
发表时间：
2020-01-01
影响因子：
22.1
通讯作者：
Zhang, Zuotai
中科院分区：
文献类型：
--
作者：
Bu, Yibin;Chen, Yafeng;Zhang, Zuotai
为了设计一种高效的甲醛氧化催化剂，需要很好地理解催化剂的结构性质与反应机理之间的关系。考察了商品CeO 2（CeO 2-C）和纳米棒CeO 2（CeO 2-R）以及相应的Au/CeO 2催化剂在甲醛氧化中的性能。反应性测试表明，Au/CeO 2-R在室温下对甲醛的氧化具有高效、稳定的性能，这归因于Au-CeO 2-R界面的高活性。Au与CeO 2-R之间的强相互作用极大地促进了界面附近氧空位和Au 3+的产生，从而促进了甲酸盐的形成。甲酸盐的转化可以遵循分解和直接氧化途径，这是显着增强的共存的Au 3+和氧空位。此外，甲酸盐的积累和Au粒子的聚集也是导致失活的主要原因.湿度的存在促进了甲酸盐的氧化，提高了Au/CeO 2催化剂在甲醛氧化中的反应活性和稳定性。
To design an efficient catalyst for HCHO oxidation, it requires good understanding of the correlation between structural properties of catalyst and the reaction mechanism. We investigated performance of commercial CeO2 (CeO2-C) and nanorod CeO2 (CeO2-R) and the corresponding Au/CeO2 catalysts in HCHO oxidation. Reactivity tests showed that Au/CeO2-R is highly efficient and stable in HCHO oxidation at room temperature, which is attributed to the highly active Au-CeO2-R interface. The strong interaction between Au and CeO2-R greatly promotes the creation of oxygen vacancies and Au3+ near the interface, which promotes the formation of formate. The conversion of formate can follow both a decomposition and a direct oxidation pathway, which is remarkably enhanced by the coexistence of Au3+ and oxygen vacancies. In addition, formate accumulation and Au particles aggregation led to deactivation. The presence of humidity promotes the oxidation of formate, which improves the reactivity and stability of Au/CeO2 in HCHO oxidation.