Zeolite Y-Encapsulated Pd Single Atoms and Clusters: Unlocking Stepwise Synergy for Low-Temperature Propane Oxidation

We report the rational design and precise construction of Y zeolite-encapsulated Pd catalysts featuring coexisting single atoms and clusters (Pd1+n@Y) that enable the efficient and low-temperature total oxidation of propane. Fine tuning of Pd loading and synthesis conditions in a PVP-assisted one-pot hydrothermal approach affords controllable confinement of dual active sites (isolated Pd single atoms and clusters). Catalytic evaluations reveal that Pd1+n@Y exhibits a T90 of only 265 °C, significantly outperforming the single-site counterparts (Pd1@Y and Pdn@Y). Combining density functional theory (DFT) calculations with in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies elucidates a stepwise synergistic mechanism wherein Pd single atoms preferentially activate the C–H bond in propane to form alkyl intermediates, while Pd clusters facilitate O2 activation and C–C bond cleavage to complete oxidation. This work establishes a robust “single atom–cluster” synergistic paradigm for designing advanced catalysts for the abatement of light alkanes.