fig6
Figure 6. Synthesis strategy and positive influence of surface PdCx species. (A) Two typical routes for incorporating C atoms into Pd lattices; (B) TEM image of the PdCx/XC72 catalyst; (C) the comparison of exchange current density of HOR over the PdCx/XC72 (solid line) and oxygen-treated PdCx/XC72 (dashed line); (A-C) reproduced with permission from[97]: Copyright 2012, Elsevier.