State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai 200237, PR China.
Environ Sci Technol. 2024 Nov 12;58(45):20300-20312. doi: 10.1021/acs.est.4c06776. Epub 2024 Oct 30.
The oxidation of chlorinated volatile organic compounds on CeO is hindered by its high susceptibility to chlorine poisoning, resulting in a reduced efficiency and stability. In this study, Ru- and Nb-co-modified CeO catalysts were designed to achieve excellent activity, stability, and CO selectivity in the catalytic oxidation of 1,2-dichloroethane (EDC). The formation of Nb-O-Ce bonds was observed to enhance the surface acidic sites, thereby improving HCl selectivity and reducing the production of chlorinated byproducts. Meanwhile, it inhibits the formation of Ru-O-Ce and promotes the generation of highly dispersed RuO particles on the surface, enhancing the redox properties and mobility of the surface oxygen, thus increasing CO selectivity. In situ diffuse reflectance infrared Fourier transform spectroscopy results revealed that chlorine species preferentially attach to Nb species rather than to oxygen vacancies on the Ru/Nb/CeO catalyst. This allows more alkane groups to oxidize to formate on the oxygen vacancies, reducing byproduct concentration. Additionally, the oxidation of alkane groups to carboxylic acids is initiated on the Nb species, completing a comprehensive oxidation process under the synergistic effect of RuO.
CeO 对氯挥发性有机化合物的氧化受到其对氯中毒高敏感性的阻碍，导致效率和稳定性降低。在这项研究中，设计了 Ru 和 Nb 共改性 CeO 催化剂，以在 1,2-二氯乙烷（EDC）的催化氧化中实现优异的活性、稳定性和 CO 选择性。观察到 Nb-O-Ce 键的形成增强了表面酸性位，从而提高了 HCl 选择性并减少了氯化副产物的生成。同时，它抑制了 Ru-O-Ce 的形成，并促进了高度分散的 RuO 颗粒在表面上的生成，增强了表面氧的氧化还原性质和迁移性，从而提高了 CO 选择性。原位漫反射红外傅里叶变换光谱结果表明，氯物种优先与 Nb 物种而不是 Ru/Nb/CeO 催化剂上的氧空位结合。这使得更多的烷烃基团在氧空位上氧化为甲酸盐，减少了副产物浓度。此外，烷烃基团在 Nb 物种上被氧化为羧酸，在 RuO 的协同作用下完成了全面的氧化过程。
