Electrochemical Storage of Atomic Hydrogen on Single Layer Graphene

• Published in: Journal of the American Chemical Society 2021-11, Vol.143 (44), p.18419-18425
• Main Authors: He, Quanfeng, Zeng, Lanping, Han, Lianhuan, Sartin, Matthew M, Peng, Juan, Li, Jian-Feng, Oleinick, Alexander, Svir, Irina, Amatore, Christian, Tian, Zhong-Qun, Zhan, Dongping
• Format: Article
• Language: English
• Subjects: Chemical Sciences
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.1c05253

If hydrogen can be stored and carried safely at a high density, hydrogen-fuel cells offer effective solutions for vehicles. The stable chemisorption of atomic hydrogen on single layer graphene (SLG) seems a perfect solution in this regard, with a theoretical maximum storage capacity of 7.7 wt %. However, generating hydrogenated graphene from H2 requires extreme temperatures and pressures. Alternatively, hydrogen adatoms can easily be produced under mild conditions by the electroreduction of protons in solid/liquid systems. Graphene is electrochemically inert for this reaction, but H-chemisorption on SLG can be carried out under mild conditions via a novel Pt-electrocatalyzed “spillover-surface diffusion-chemisorption” mechanism, as we demonstrate using dynamic electrochemistry and isotopic Raman spectroscopy. The apparent surface diffusion coefficient (∼10–5 cm2 s–1), capacity (∼6.6 wt %, ∼85.7% surface coverage), and stability of hydrogen adatoms on SLG at room temperature and atmospheric pressure are significant, and they are perfectly suited for applications involving stored hydrogen atoms on graphene.