Fig. 13

a, b STM images showing atomically dispersed Pd atoms on a Cu(111) surface and hydrogen atoms that have dissociated and spilled over onto the Cu surface. c Potential energy diagram depicting the mode of action of a Pd SAA surface compared with those of pure Cu(111) and Pd(111). d–e HAADF-STEM images showing the morphology of γ-Al₂O₃-supported Pt/Cu SAA. a–c Adapted with permission from Ref. [144]. Copyright 2012, American Association for the Advancement of Science. d–e Adapted with permission from Ref. [147]. Copyright 2018, Nature Publishing Group