[ACIE] 我室李剑锋教授发表论文:Probing Interfacial Electronic and Catalytic Properties on Well‐Defined Surfaces Using In Situ Raman Spectroscopy

我室李剑锋教授在 ACIE 上发表论文:Probing Interfacial Electronic and Catalytic Properties on Well‐Defined Surfaces Using In Situ Raman Spectroscopy

文章链接:https://onlinelibrary.wiley.com/doi/10.1002/anie.201805464

摘要:

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, yet necessary for clearly elucidating the catalytic mechanism. Herein, two types of model interfaces, namely Pd and Pt overlayers on Au single crystals, were precisely 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 (νNC) was observed, which was 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. This work provides a novel approach to probing electronic structures of heterogeneous metal interfaces, illuminating understanding of catalytic mechanisms at the molecular level.