Surface Enrichment of Pd_<i>x</i>Ce_1–<i>x</i>O_2−δ Solid-Solution Nanoparticles on Porous TiO₂ Frameworks for Efficient Catalytic CO Oxidation

In this work, an efficient and stable catalyst composed of PdxCe1–xO2−δ solid-solution nanoparticles supported on porous TiO2 frameworks was developed, employing a two-step method comprising in situ etching of Ti-based metal–organic frameworks (MOFs) and subsequent calcination. During the synthetic process, the MOF-hydrolyzed TiO2 nanosheet networks served as structural scaffolds, efficiently maintaining the integrity of the basic architecture of the MOFs without distinct shrinking under calcination. Meanwhile, the introduced Pd species entered the CeO2 lattice on the surface, forming solid-solution nanoparticles that acted as stable active sites for CO oxidation. The resulting material possessed strong electronic interactions and an optimized reduction temperature, indicating that complete CO conversion could be achieved at 90 °C with a stable operation for 60 h at this temperature. We believe that this work not only offers a promising catalyst candidate for practical CO treatment but also shows a facile synthetic strategy for achieving MOF-derived highly active and stable hybrid catalysts.