fig2

Figure 2. TEM (i, ii), HRTEM (iii, iv), HAADF (v) images and the corresponding elements mapping (vi, vii) of Pd-U-ace-NH (A), Pd-U-ace-SN (B) and Pd-U-ace-SN-F (C). TEM: Transmission electron microscope; HRTEM: high-resolution TEM; HAADF: high-angle annular dark-field.