Metal-organic framework-derived one-dimensional Pd@CeO2 catalysts with enhanced activity for methane oxidation

The interfacial structure in heterogeneous catalysis is important for effective and sequential methane oxidation due to its unique electronic structure. Here, we propose a facile strategy to fabricate a unique 1D [email protected]2-BDC catalyst from a corresponding [email protected] bimetallic metal − organic frameworks (MOFs) nanostructure through thermal progress. By combining analysis of XRD, Raman, TEM, HRTEM and XPS results, the 1D mesoporous [email protected]2-BDC catalysts were rich in oxygen vacancies, and the Pd species were uniformly distributed on CeO2 (1 1 0) surface in the form of small PdO clusters and PdxCe1-xO2-σ species. By reason of intense metal support interaction in the MOF skeleton, partial Pd atoms supersede Ce4+ in CeO2 lattice, which can significantly impact the catalyst's structure and electronic properties. H2-TPR and O2-TPD revealed that the aliovalent-substituted of Pd and Ce can greatly expedite the formation of active oxygen species and improve the redox properties, therefore stimulating an extraordinary catalytic properties for methane combustion. At a high space velocity of 60,000 mLg-1h−1, the 1 % [email protected]2-BDC catalyst achieved excellent catalytic performance with 90 % methane purification at 342 °C. More importantly, in situ DRIFTS and density functional theory (DFT) calculations were conducted to establish the structure–activity relationship and reveal the reaction mechanism, proving that the excellent reactivity of MOF-derived catalysts can be attributed to lower energy barriers for methane activation on the reconstructed surfaces than surface adsorbed PdO. The present development for MOF-derived catalysts provides a new horizon for the construction of lean methane combustion catalysts.