Regulation of catalytic reaction performance of CO2 with ethane by metal cation substitution on CeO2 support.

[Display omitted] • Simultaneously realized the value-added conversion of greenhouse gas CO 2 and natural gas. • C 2 H 4 selectivity reached 82.7 % on 2 % Ti-substituted Fe 1.5 Ni 0.5 /CeTi-C-2 catalyst. • The substitution of Ti induces the generation of oxygen vacancies O v to promote the reaction. • Activation energy barrier of CO 2 on Ti-CeO 2 (111) decreased from 3.87 eV to 2.17 eV. The catalytic reaction of CO 2 with ethane balances the resourceful conversion of CO 2 and the value-added utilization of shale gas. In this paper, the effects of different metal cation substitutions on CeO 2 support in Fe-Ni catalysts on the regulation of CO 2 and ethane directional catalytic reaction performance were studied through experiments combined with DFT calculation simulations. It was found that the Ti-substituted Fe 1.5 Ni 0.5 /CeTi-2 catalyst had the highest ethane conversion of 11.8% and CO 2 conversion of 21.2%, and presented a high-value product C 2 H 4 selectivity higher than 80%. The Ti/La species in the substituted structure are highly dispersed into the CeO 2 lattice to form a Ti/La x Ce 1-x O 2−δ solid solution, which induces more (-111) and (110) crystal planes with high ethylene selectivity. The Ti-substituted catalyst has the highest proportion of Ce3+, which improves the formation and transfer of active oxygen, making Fe 1.5 Ni 0.5 /CeTi-C-2 exhibit higher catalytic reactivity. The substitution of metal cations weakens the adjacent Ce-O bond strength, and the Ti substitution structure facilitates the generation of O v as a highly active center for CO 2 reduction, resulting in a decrease of the energy barrier for the CO 2 dissociation process from 3.87 eV on pristine CeO 2 (111) to 2.17 eV, and the reaction energy endotherm is 1.03 eV. Both kinetically and thermodynamically, the reduction dissociation of CO 2 on Ti-CeO 2 (111) is more competitive than that on Zr and La-substituted CeO 2 (111). [ABSTRACT FROM AUTHOR]