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Probing Interfacial Electronic and Catalytic Properties on Well‐Defined Surfaces by Using In Situ Raman Spectroscopy
Author(s) -
Wang YaHao,
Liang MiaoMiao,
Zhang YueJiao,
Chen Shu,
Radjenovic Petar,
Zhang Hua,
Yang ZhiLin,
Zhou XiaoShun,
Tian ZhongQun,
Li JianFeng
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201805464
Subject(s) - x ray photoelectron spectroscopy , raman spectroscopy , in situ , characterization (materials science) , catalysis , materials science , molecule , spectroscopy , metal , electrochemistry , electronic structure , chemistry , nanotechnology , electrode , chemical engineering , computational chemistry , physics , optics , organic chemistry , quantum mechanics , engineering , metallurgy , biochemistry
Heterogeneous metal interfaces play a key role in determining the mechanism and performance of catalysts. However, in situ characterization of such interfaces at the molecular level is challenging. Herein, two model interfaces, Pd and Pt overlayers on Au single crystals, were constructed. The electronic structures of these interfaces as well as effects of crystallographic orientation on them were analyzed by shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) using phenyl isocyanide (PIC) as a probe molecule. A clear red shift in the frequency of the C≡N stretch (ν NC ) was observed, which is consistent with X‐ray photoelectron spectroscopy (XPS) data and indicates that the ultrathin Pt and Pd layers donate their free electrons to the Au substrates. Furthermore, in situ electrochemical SHINERS studies showed that the electronic effects weaken Pt−C/Pd−C bonds, leading to improved surface activity towards CO electrooxidation.