Copper-doped CeZn catalysts for efficient CO2-assisted oxidative dehydrogenation of propane: Mechanistic insights and performance optimization

The use of CO 2 as a mild oxidant for the oxidative dehydrogenation of propane (CO 2 -ODHP) is crucial for achieving net-zero carbon emissions and mitigating greenhouse gases that contribute to global warming. In this study, a CeZn catalyst was synthesized using the wet impregnation method and applied for CO 2 -ODHP. Incorporating Cu into the (CeZn) lattice enhanced both propane conversion and yield by leveraging the redox properties of (CeZn) to activate CO 2 into CO and O*, which facilitated the cleavage of propane C-H bonds. Characterization of the catalyst’s physicochemical properties revealed that doping Cu into (Ce/Zn) significantly increased the specific surface area and pore volume due to the presence of Cu 2+ species, promoting the mobility of lattice oxygen (O Lat ), and thereby improving C 3 H 8 conversion. Additionally, the transfer of oxygen from Ce 4+ to Ce 3+ during the reaction contributed to the highest propene selectivity observed for the copper-free catalyst. The catalytic activity was maintained even after several hours of propane conversion at 550°C. All catalysts demonstrated relatively stable performance, with the highest and lowest relative deactivation rates of less than 6% and 4%, respectively, observed in 0%Cu(Ce/Zn) and 3%Cu(Ce/Zn). DFT calculations revealed that the CuO-ZnO cluster on the CeO 2 (111) surface effectively promotes the activation of CO 2 . Thus, modifying (Ce/Zn) with Cu is a promising strategy for enhancing propene yield in CO 2 -ODHP.