Surface composition of magnetron sputtered Pt-Co thin film catalyst for proton exchange membrane fuel cells

In-situ electrochemical atomic force microscopy study of aging of magnetron sputtered Pt-Co nanoalloy thin films during accelerated degradation test

“…Since the particle size effect on BE shift can be excluded (the size of the particles measured by AFM was almost the same for as-deposited Pt and Pt-Co), the shift confirms the formation of the Pt-Co alloy in case of the asdeposited Pt-Co thin film [31]. Moreover, the core level shifts of 0.2 eV match the theoretical and experimental value reported previously for Pt-Co alloy [31,18,33,34]. However, for Pt-Co after 2000 CV cycles the Pt 4f spectrum shifts back to the BE value for pure Pt, indicating again the catalyst dealloying and formation of Pt surface on top of the Pt-Co catalyst after aging test.…”

“…Although the number of publications devoted to PtCo materials obtained by physical deposition methods is relatively small [14][15][16][17], it has been proved that a catalyst prepared in such a way is also promising for ORR. In our previous studies we have showed that simultaneous magnetron sputtering of Pt and Co leads to the formation of Pt-Co alloy catalyst film [18,19]. Moreover, we have successfully demonstrated a high mass activity and excellent stability of such thin film catalyst in PEMFC [20].…”

Pd Single-Atom Sites on the Surface of PdAu Nanoparticles: A DFT-Based Topological Search for Suitable Compositions

“…In the chemical ordering calculations in the larger NP 586 and NP 1289 models the last verifying step by exceedingly demanding DFT calculations was omitted, fully relying on the E TOP energies. Applications of this method [ 20 , 21 ] to various bimetallic NPs revealed that E TOP expressions despite their simplicity are sufficient for very efficient determining reliable atomic distributions in the energetically most stable homotops, in good agreement with DFT data [ 14 , 15 , 39 , 40 , 41 , 42 , 43 , 44 ].…”

Nanoscale architecture of ceria-based model catalysts: Pt–Co nanostructures on well-ordered CeO2(111) thin films

“…However, according to density functional theory (DFT) calculations [52,53], the chemical ordering in Pt-Co nanoalloys strongly depends on the size and the stoichiometry of the nanoparticles. For instance, in Co-rich nanoparticles, Pt tends to segregate to the surface where it occupies corner and edge sites while terrace sites are mostly occupied by Co. With increasing Pt content, most of the Pt atoms segregate to the surface, although a fraction of Pt atoms was found in the core as well [52].…”