fig4

Figure 4. Size effect exhibited by small Cu nanoclusters. (A) Ball models of spherical Cu NPs with 2.2 and 6.9 nm diameters. Surface atoms are colour-coded according to their first-neighbour CN: CN < 8 (grey), CN = 8 (blue), CN = 9 (red), CN > 9 (green); (B) Population (relative ratio) of surface atoms with a specific CN as a function of particle diameter. (A and B) Reproduced with permission from Ref.^[84], Copyright © 2014 American Chemical Society; (C) Size-dependent selectivity for main products. Reproduced with permission from Ref.^[85], Copyright © 2016 American Chemical Society. NPs: Nanoparticles: CN: coordination number.