Development and Simulation of Sulfur‐doped Graphene Supported Platinum with Exemplary Stability and Activity Towards Oxygen Reduction

Abstract

Sulfur‐doped graphene (SG) is prepared by a thermal shock/quench anneal process and investigated as a unique Pt nanoparticle support (Pt/SG) for the oxygen reduction reaction (ORR). Particularly, SG is found to induce highly favorable catalyst‐support interactions, resulting in excellent half‐cell based ORR activity of 139 mA mgPt −1 at 0.9 V vs RHE, significant improvements over commercial Pt/C (121 mA mgPt −1) and Pt‐graphene (Pt/G, 101 mA mgPt −1). Pt/SG also demonstrates unprecedented stability, maintaining 87% of its electrochemically active surface area following accelerated degradation testing. Furthermore, a majority of ORR activity is maintained, providing 108 mA mgPt −1, a remarkable 171% improvement over Pt/C (39.8 mA mgPt −1) and an 89% improvement over Pt/G (57.0 mA mgPt −1). Computational simulations highlight that the interactions between Pt and graphene are enhanced significantly by sulfur doping, leading to a tethering effect that can explain the outstanding electrochemical stability. Furthermore, sulfur dopants result in a downshift of the platinum d‐band center, explaining the excellent ORR activity and rendering SG as a new and highly promising class of catalyst supports for electrochemical energy technologies such as fuel cells.

Nanotechnology for environmentally sustainable electromobility

“…A catalyst support would ideally maximize the catalyst surface area available for reactions and maintain high electric conductivity for high energy efficiency. Supports made of carbon black currently used in commercial PEMFC catalysts are vulnerable to corrosion, which causes catalyst sintering and decreases the amount of conductive material in the electrode, thereby decreasing power density and PEMFC lifetime 29,151 . Carbon black-based support materials also suffer from deep micropores that physically block reagent access to the catalyst and thus decrease catalyst efficiency 152 .…”

“…Data from carbon black from references 47,50,51,280 ; data from carbon-based nanostructures from references 31,47,50,51,56,60,154,177,[281][282][283][284][285][286][287][288][289][290][291][292] ; data from carbon-based polymer composites from references 47,50,51,56,86,[293][294][295][296] ; data from carbon-based N-, P-, S-doped nanostructures from references 47,50,51,56,66,151,152,154,283,[297][298][299] ; data from carbon-based SnO2, -TiO2 composites from references 47,50,51,56,66,86,...…”

Sulfur and Nitrogen Codoped Carbon Tubes as Bifunctional Metal‐Free Electrocatalysts for Oxygen Reduction and Hydrogen Evolution in Acidic Media

“…In this case, since NCT has more inert surface than the carbonaceous tubes, S and N species from cysteine are difficult to incorporate into the carbon matrix (Supporting Information, Figure S10). [16] Except for the superior ORR activity, SNCT is also impressed by the high electron transfer number (n) and stability. The n value for SNCT varies in a small range of 3.95-3.85, and H 2 O 2 yield within 2-8 % (Figure 2 e), as calculated from the rotating ring disk electrode (RRDE) curves (Supporting Information , Figure S11).…”

Computational chemistry for graphene-based energy applications: progress and challenges

“…These authors correlated these ε dc values with the adsorption energy of an oxygen atom on the supported PtNP; oxygen binding was weakest for the N-doped graphene support, thus supporting the prediction that PtNPs supported by N-doped graphene could improve ORR kinetics. In a similar vein, Higgins et al 184 explained the superior ORR kinetics of the Pt/S-doped graphene system via the calculated negative shift in ε dc values for supported Pt 13 compared with undoped graphene.…”

“…The authors also predicted that the cohesive energy of the cuboctahedral Pt 55 NP adsorbed via a {111} facet would be enhanced on N-doped graphene relative to the pristine substrate. Recently, PW-DFT PBE calculations of the binding properties of sulful-doped graphene with respect to Pt atoms and PtNPs 184 . S-doped graphene led to relatively stronger binding of Pt atoms compared with the undoped case.…”