Modulated CO Oxidation Activity of M-Doped Ceria (M = Cu, Ti, Zr, and Tb): Role of the Pauling Electronegativity of M

Many properties of dopants have been investigated to explore the key factor that influenced the CO oxidation activity of M-doped ceria (CeM). Nevertheless, these reports were controversial. Herein, the Pauling electronegativity (chi(P)) of the M was presented as a convenient guide to screen a proper dopant for ceria. Kinetics results indicated that the T-10 (the temperature when CO conversion reached 10%) of CeM73 catalysts (Ce/M molar ratio was 7/3; M = Cu, Ti, Zr, and Tb) was linearly dependent on the chi(P) of the M, which could adjust the amount of active lattice oxygen (A(OL)). The A(OL) was important to catalyst activity because lattice oxygen extraction was the rate-determining step in the overall reaction.