Yttrium Doping in Fe/ZrO2 for Enhanced CO2-Ethane Oxidative Dehydrogenation via Promoting Oxygen Vacancy Formation and Lattice Oxygen Mobility

CO 2 -assisted oxidative dehydrogenation of ethane to ethylene is a potential low-carbon process for CO 2 utilization and ethane upgrading. The key bottleneck of this reaction is the extent to which catalytic active sites can efficiently activate C=O bonds in CO 2 and precisely control the selective cleavage of C–C/C–H bonds in ethane. Herein, combined with catalytic activity evaluation, catalyst characterization, and density functional theory (DFT) calculations, this study systematically investigates the effect of rare earth metal (Ce, La, and Y) modification on the performance of Fe/ZrO 2 catalysts in ethane dehydrogenation with CO 2 . The results demonstrate that the Y-modified 3Fe/3Y-ZrO 2 catalyst achieves an ultrahigh C 2 H 4 selectivity of 89.8%. The underlying mechanism is as follows: Y doping markedly strengthens the metal-support interaction and lowers the formation energy of oxygen vacancies, thereby generating more oxygen vacancies. This enhancement promotes the mobility of active oxygen species, facilitating the release of more lattice oxygen, which acts as active sites to efficiently promote the cleavage of C–H bonds in ethane, thereby improving ethylene selectivity. Meanwhile, the O* species derived from reductive oxygen vacancies (O v ) are replenished through the cleavage of C=O bonds in CO 2 , further strengthening CO 2 activation. Additionally, Y doping enhances the specific surface area and pore volume of the 3Fe/3Y-ZrO 2 catalyst, increasing the exposure of active sites and further enhancing catalytic performance. This study provides novel research insights for the directed high-value conversion of CO 2 .