Ultra-efficient Ru and Nb Co-Modified CeO Catalysts for Catalytic Oxidation of 1,2-Dichloroethane.

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.