In Situ Hard X-ray Photoelectron Study of O-2 and H2O Adsorption on Pt Nanoparticles
In Situ Hard X-ray Photoelectron Study of O-2 and H2O Adsorption on Pt Nanoparticles
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Pt 纳米粒子吸附 O-2 和 H2O 的原位硬 X 射线光电子研究
DOI：
10.1021/acs.jpcc.6b02402
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发表时间：
2016
影响因子：
3.7
通讯作者：
Oshima Masaharu
中科院分区：
文献类型：
--
作者：
Cui Yitao;Harada Yoshihisa;Ikenaga Eiji;Li Rui;Nakamura Naoki;Hatanaka Tatsuya;Ando Masaki;Yoshida Toshihiko;Li Guo-Ling;Oshima Masaharu
为了提高聚合物电解质燃料电池中基于pt的阴极催化剂的效率，在分子水平上理解表面和界面上的氧还原过程是必不可少的。在本研究中，采用原位硬x射线光电子能谱（HAXPES）研究了作为还原过程第一步的H2O和o2的吸附和解离。Pt纳米粒子对H2O和o2吸附的Pt 5d价带和Pt 3d、Pt 4f核HAXPES光谱显示，H2O吸附对Pt电子结构的影响可以忽略不计，而o2吸附则有显著的影响，分别反映了H2O和o2对Pt纳米粒子的弱和强化学吸附。结合从头算理论计算，得出了导致Pt - o2成键的p5d态位于距离费米能级2 eV以内的结论。
To improve the efficiency of Pt-based cathode catalysts in polymer electrolyte fuel cells, understanding of the oxygen reduction process at surfaces and interfaces in the molecular level is essential. In this study, H2O and O2adsorption and dissociation as the first step of the reduction process were investigated by in situ hard X-ray photoelectron spectroscopy (HAXPES). Pt 5d valence band and Pt 3d, Pt 4f core HAXPES spectra of Pt nanoparticles upon H2O and O2adsorption revealed that H2O adsorption has a negligible effect on the electronic structure of Pt, while O2adsorption has a significant effect, reflecting the weak and strong chemisorption of H2O and O2on the Pt nanoparticle, respectively. Combined with ab initio theoretical calculations, it is concluded that Pt 5d states responsible for Pt–O2bonding reside within 2 eV from the Fermi level.