Extending the limits of Pt/C catalysts with passivation-gas-incorporated atomic layer deposition

A Double‐Passivation Water‐Based Galvanic Displacement Method for Reproducible Gram‐Scale Production of High‐Performance Platinum‐Alloy Electrocatalysts

“…As recently showcased in a study by Xu and co‐workers, an analogous concept utilizing the strong Pt‐CO coupling was demonstrated in the gas phase using atomic layer deposition of Pt precursor in presence of CO, favoring deposition on the new positions of the carbon support instead of deposition on already formed Pt NPs. In short, the double passivation method involves blockage of two out of three possible paths of least resistance for electrons and thus preferential deposition of Pt cations during GD on fresh spots on carbon support as the only remaining viable path for electrons.…”

“…On the other hand, there is a significant difference in the most intense peaks corresponding to the PtCu phase −41.2 (111) and 47.9° (200) 2 θ . The obtained difference is a direct consequence of a strong Pt‐CO interaction where CO acts as a very efficient capping agent, preventing excessive agglomeration and growth of the formed NPs by passivation of the Pt surface. After the subsequent thermal annealing of both analogues (Figure b), the difference in obtained XRD spectra of both analogues becomes even more expressed, indicating a much smaller crystallite size in the case of PtCu 3 /C‐CO.…”

A Double‐Passivation Water‐Based Galvanic Displacement Method for Reproducible Gram‐Scale Production of High‐Performance Platinum‐Alloy Electrocatalysts

“…On the other hand, there is asignificant difference in the most intense peaks corresponding to the PtCu phase À41.2 (111) and 47.98 8 (200) 2q. Theo btained difference is adirect consequence of astrong Pt-CO interaction where CO acts as av ery efficient capping agent, [19][20][21] preventing excessive agglomeration and growth of the formed NPs by passivation of the Pt surface.A fter the subsequent thermal annealing of both analogues (Figure 2b), the difference in obtained XRD spectra of both analogues becomes even more expressed, indicating am uch smaller crystallite size in the case of PtCu 3 /C-CO.T of urther confirm the observed differences in XRD spectra from Figure 2a (Figure 2d), we observe an ear-perfect dispersion of PtCu NPs.A fter the subsequent thermal annealing, poorly dispersed and agglomerated PtCu nanocrystallites sinter into larger particles (Figure 2e). In contrast, optimally dispersed PtCu particles remained small and well dispersed also after the thermal treatment (Figure 2f).…”

The loading effect of Pt clusters on Pt/graphene nano sheets catalysts

“…However, the metal loading density must be kept low (usually below 0.5%) to avoid the formation of metal nanoparticles through sintering 22 . The nanoscales materials may be designed referring to controllable transportation, separation, classification of nano-objects 23 and type of supporting materials 24 . Their electronic properties and catalytic activity are tuned by the interaction between the central metal and the neighboring surface atoms, and their atomically dispersed nature allows for metal utilization of up to 100% 25 .…”