fig7

Figure 7. Examination of Pd sintering as a function of annealing temperature. (A) STM image of 0.1 Pd atoms/u.c. at room temperature compared to (B) the same surface after heating to 550 K. (C) XPS Pd 3d_5/2 data showing the fraction amount of Pd single atoms for surfaces with 0.1 Pd atoms/u.c. for a surface free of adsorbates (black points) and a surface covered with methanol/ methoxy (red points). Reproduced from Ref.^[89] with permission from the American Chemical Society. (D) Light-off test of CO oxidation ([CO] = 1%, [O₂] = 20% and balanced with N₂ at a GHSV of 80,400 mL·gcat^-1·h^-1), (E) H₂-TPR rofiles over 1CuCe catalysts with different calcination temperatures. XANES spectra of (F) 1CuCe-800 and (G) 1CuCe-400. Extended x-ray absorption fine structure (EXAFS) spectra of (H) CuCe-800 and (I) 1CuCe-400. Reproduced from Ref.^[108] with permission from the American Chemical Society.