Suppressing Dissolution of Pt‐Based Electrocatalysts through the Electronic Metal–Support Interaction

Abstract

Suppressing the Pt dissolution still remains a big challenge in improving the long‐term stability of Pt‐based catalysts in electrochemical energy conversion. In this work, the degradation of Pt nanoparticles is successfully suppressed via weakening the Pt–O dipole effect by adjusting the electronic structure of surface Pt atoms. The specially designed graphitic‐N‐doped carbon nanosheets with balanced N content and graphitization degree as well as fewer defects are prepared for anchoring Pt nanoparticles to enhance the electronic metal–support interaction. This can accelerate the electron transfer from Pt to substrate, decrease the surface electron density of Pt, and attenuate the Pt–O interaction. As a result, the rate of Pt dissolution decreases by 95% compared to that of commercial Pt/C toward the oxygen reduction reaction and thus the catalytic stability is significantly improved in the electrochemical accelerated durability test. The theoretical simulation shows that the inhibition of surface Pt dissolution is attributed to the enhanced energy barrier in the initial relaxation process.

Manipulating the electronic configuration of Fe–N4sites by an electron-withdrawing/donating strategy with improved oxygen electroreduction performance

“…2h), which indicated the weaker dipole effect between the Fe centers and chemisorbed oxygen in Fe-SA/BNC. 43,44 This result further established that B-doping could optimize the desorption of the oxygen intermediates during the ORR process by modulating the electronic configuration of adjacent Fe–N 4 sites.…”

Graphene-Derived Carbon Support Boosts Proton Exchange Membrane Fuel Cell Catalyst Stability

“…A higher sp 2 carbon content and fewer structural defects (lower I D / I G ratio) of GD materials could provide for different MSI that favors better ECSA CO as well as MA retention after the ADT. Although the exact correlation of MSI and its effect on the durability of the PEMFC catalysts is not yet well understood and defined, the results within this study suggest that this parameter could play an important role in understanding the origin of better catalyst durability and should therefore be further addressed in upcoming studies. , …”

“…Although the exact correlation of MSI and its effect on the durability of the PEMFC catalysts is not yet well understood and defined, the results within this study suggest that this parameter could play an important role in understanding the origin of better catalyst durability and should therefore be further addressed in upcoming studies. 41 , 42 …”

“…This could mean that in this case, the carbon support has a positive effect on the stability of the electrocatalyst presented in Figure 3 and its kinetic activity measured in the real GDE catalyst layer which could in theory also be attributed to the different MSI. 41 , 42 …”

Native Ligand Carbonization Renders Common Platinum Nanoparticles Highly Durable for Electrocatalytic Oxygen Reduction: Annealing Temperature Matters

“…In addition, we also evaluated the dissolution of Pt NPs by analyzing the Pt species dissolved in electrolytes after 20k cycles by ICP‐MS, which showed that the dissolved Pt content for Pt‐700 catalysts was substantially lower than that for Pt/C (0.232 ng vs 40 ng). [ 49 ] The Pt particles from the Pt/C catalyst are ≈1.7× smaller than those from the Pt‐700 catalyst (≈3 nm vs 5 nm), and it is well known that smaller Pt particles are more prone to dissolution than larger ones. [ 50–52 ] However, the antidissolution improvement of ≈170× far exceeds what would be expected based purely on differences in the particle size, and suggests that a further electronic effect may be largely responsible for the difference in Pt dissolution.…”