Lanthanide modified Pt/CeO2-based catalysts for methane partial oxidation: Relationship between catalytic activity and structure

Abstract

In most cases, reasonable design and construction of Pt/CeO2-based catalysts and detailed exploration of relationship between its structural characteristics and the catalytic activity are crucial to improve the catalytic performance and reduce the cost. In this work, a series of CeO2 doped with lanthanide metal ions (La, Nd, Er and Yb) has been successfully synthesized, and then Pt is introduced through impregnation. The morphology, structure and component analysis are characterized by SEM, TEM (HRTEM), EDS, XRD, ICP-AES, XPS, UV Raman, O2-TPD, H2-TPR and CO or O2-pulse chemisorption, and the corresponding catalytic performances are developed by partial oxidation of methane. On the basis of the analysis of the structural properties of various catalysts, it is found that the Pt/CeLa catalyst shows the best catalytic performance due to its low valence state of Pt, excellent oxygen migration capacity and oxygen storage capacity, T50 is 510 °C and the selectivity is superiority. What's more, the modification of CeO2 by lanthanide metal ions especially La3+ can effectively change the oxygen activity of supports, so that this catalyst can be used in various redox catalytic reactions.