Ultrafine Pd species anchored on porous CeO2 nanobundles as a highly efficient catalyst for methane oxidation

Ultrafine Pd species embedded in porous CeO 2 matrix derived from Ce-MOFs were facilely prepared. The mixed chemical states of Pd species along with abundant oxygen vacancies contribute to high catalytic activity. • Pd/CeO 2 nanobundles derived Ce-MOF were facilely prepared. • Unltrafine Pd species are homogeneously embedded in porous CeO 2 matrix. • The Pd/CeO 2 nanobundles show obviously improved catalytic activity at low temperature. • Mixed chemical states of Pd species along with abundant oxygen vacancy contribute to high activity. The design and development of efficient catalyst is very important for the removal of air pollutants through catalytic oxidation technology. Here, the Pd/CeO 2 catalysts were synthesized via in-situ thermal pyrolysis of Pd 2+ doped Ce-MOF. The prepared Pd/CeO 2 -NB catalyst exhibits nanobundles structure and highly dispersed Pd species, which shows superior performance in CO oxidation and CH 4 combustion at low temperature (<400 °C). The Raman, XPS, TPR and CO-IR reveal that the Pd/CeO 2 -NB sample has a certain surface concentration of Pd 0 species, and the formed Pd/PdO species boost the generation of oxygen vacancies, facilitating the dissociation of gas oxygen and the diffusion of lattice oxygen. Besides, possible reaction mechanism is also clarified by in-situ DRIFTS spectra, and main surface intermediate species (carbonate and carbon oxygenates) were confirmed. This study paves a way for the design of MOFs-based catalytic materials.