Fig. 3: In situ atomic-scale observations of Pd redox dynamics.
From: Redox dynamics and surface structures of an active palladium catalyst during methane oxidation
Oscillatory phase transition between Pd and PdO on the metallic surface (a–c) and the oxide surface (h–j) at 550 °C in the gas mixture of CH4, O2, and He (p(CH4) = 36.7 mbar, p(O2) = 16.7 mbar and p(He) = 126.6 mbar). Insets show FFTs of the corresponding HRTEM images. d, e Inverse Fourier transform image and line profiles of regions close to and away from the PdO/Pd interface. f, g Inverse Fourier transform image and line profiles of regions close to and away from the PdO/Pd interface. k HRTEM image and (l) enlarged HRTEM images from the dashed rectangle in (k), revealing the presence of a monolayer PdOx on Pd. The inset of (l) illustrates the atomic model. m Lattice d-spacing analysis. Electron dose rates for (a–c), (h–j), and (k) were 2.5 × 105, 1.6 × 105, and 2.5 × 105 e·nm−2 s−1, respectively.
