Chain effect of Mn⁴⁺/ Mn³⁺ and O_Lattice on La_1-xSr_xMnO₃ catalysts for lower thermally driven CO oxidation

In this work, a series of La_1-xSr_xMnO₃ catalysts for CO oxidation were successfully fabricated via a facile sol-gel method with multistage calcination. By modifying the Sr doping quantity at A-site, the surface Mn⁴⁺/ Mn³⁺ ratio was manipulated, and thus lattice oxygen and oxygen vacancy concentrations of were further regulated by the system electron migration. This domino effect produced a radically different catalytic response, of which the optimal La_0.4Sr_0.6MnO₃ samples performed the most excellent CO oxidation at lower temperature window. In-situ DRFITS spectra revealed catalytic intermediates and demonstrated the concurrence of dominant Mv-K mechanism and secondary E-R reaction pathway in CO oxidation over La_0.4Sr_0.6MnO₃ under three types of thermodynamic states. The study is poised to enhance the propagation and practical employment of Sr-doped LaMnO₃ perovskite catalysts, while supplying theoretical perspectives for the investigation towards underlying CO reaction mechanisms.