Dresden 2020 – wissenschaftliches Programm
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O 51.2: Poster
Dienstag, 17. März 2020, 18:15–20:00, P2/1OG
probing water overlayer on Pt(111) by noncontact atomic force microscopy — •Sifan You1, Jing Guo1,2, Duanyun Cao1, Ji Chen1, Xinzheng Li1, Limei Xu1,3, Enge Wang1,3, and Ying Jiang1,3 — 1School of Physics, Peking University, Beijing 100871, P. R. China — 2Beijing Normal University, Beijing 100875, P. R. China — 3Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
As a common and efficient catalyst in electrochemical reactions, platinum has attracted lots of attentions. Imaging the water structures at atomic level may help us to achieve a better understanding of electrical double layer near the electrode and active sites during the catalytic process. Using qPlus-based noncontact atomic force microscopy, here we were able to image partial dissociation of the first water overlayer on Pt(111) with unprecedented resolution. For the root square 37 structure, it is consistent with the previous results, showing a mixture of 5-6-7 water rings. Combined with X-ray photoelectron spectroscopy, we identify the structural evolvement of the water layer from intact *37**37 phase to a partially dissociated 3*3 phase after low-temperature annealing. Temperature and isotope dependent measurements clearly show that the transition involves a proton tunneling process, which is facilitated by a collective rearrangement of H-bonding network. This work reveals the key role of nuclear quantum effects in the surface-catalyzed water dissociation.