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

• Published in: Advanced functional materials Vol. 24; no. 27; pp. 4325 - 4336
• Main Authors: Higgins, Drew, Hoque, Md Ariful, Seo, Min Ho, Wang, Rongyue, Hassan, Fathy, Choi, Ja-Yeon, Pritzker, Mark, Yu, Aiping, Zhang, Jiujun, Chen, Zhongwei
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 16-07-2014
• Subjects: catalyst; Catalysts; Computation; Computer simulation; electrochemistry; fuel cell; Graphene; oxygen reduction; Platinum; Reduction; Stability; Sulfur
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201400161

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.
Platinum supported on sulfur doped graphene (Pt/SG) is found to provide excellent oxygen reduction activity and stability. Experimental investigations indicate that utilizing SG as a support significantly improves the activity and stability of platinum nanoparticles in comparison to pure graphene, and commercial carbon supported platinum. Complementary computational simulations highlight the interactions between platinum and graphene are enhanced significantly by sulfur‐doping.