Wella Sasfan Arman, Hamamoto Yuji, Morikawa Yoshitada, Hamada Ikutaro
Department of Precision Science and Technology, Graduate School of Engineering, Osaka University 2-1 Yamada-oka, Suita Osaka 565-0871 Japan
Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jalan Ganesha 10 Bandung 40132 Indonesia.
Nanoscale Adv. 2019 Jan 8;1(3):1165-1174. doi: 10.1039/c8na00236c. eCollection 2019 Mar 12.
Single-atom catalysis, which utilizes single atoms as active sites, is one of the most promising ways to enhance the catalytic activity and to reduce the amount of precious metals used. Platinum atoms deposited on graphene are reported to show enhanced catalytic activity for some chemical reactions, methanol oxidation in direct methanol fuel cells. However, the precise atomic structure, the key to understand the origin of the improved catalytic activity, is yet to be clarified. Here, we present a computational study to investigate the structure of platinum adsorbed on graphene with special emphasis on the edges of graphene nanoribbons. By means of density functional theory based thermodynamics, we find that single platinum atoms preferentially adsorb on the substitutional carbon sites at the hydrogen terminated graphene edge. The structures are further corroborated by the core level shift calculations. Large positive core level shifts indicate the strong interaction between single Pt atoms and graphene. The atomistic insight obtained in this study will be a basis for further investigation of the activity of single-atom catalysts based on platinum and graphene related materials.
单原子催化利用单原子作为活性位点，是增强催化活性和减少贵金属用量的最有前景的方法之一。据报道，沉积在石墨烯上的铂原子对某些化学反应（如直接甲醇燃料电池中的甲醇氧化）表现出增强的催化活性。然而，精确的原子结构作为理解催化活性提高根源的关键，仍有待阐明。在此，我们进行了一项计算研究，以特别关注石墨烯纳米带边缘的方式研究吸附在石墨烯上的铂的结构。通过基于密度泛函理论的热力学方法，我们发现单个铂原子优先吸附在氢终止的石墨烯边缘的替代碳位点上。这些结构通过芯能级位移计算得到进一步证实。大的正芯能级位移表明单个铂原子与石墨烯之间有很强的相互作用。本研究中获得的原子层面的见解将为进一步研究基于铂和石墨烯相关材料的单原子催化剂的活性奠定基础。
