Probing the electronic and catalytic properties of a bimetallic surface with 3  nm resolution

Nature Nanotechnology 12, 132 (2017). doi:10.1038/nnano.2016.241 Authors: Jin-Hui Zhong, Xi Jin, Lingyan Meng, Xiang Wang, Hai-Sheng Su, Zhi-Lin Yang, Christopher T. Williams & Bin Ren An atomic- and molecular-level understanding of heterogeneous catalysis is required to characterize the nature of active sites and improve the rational design of catalysts. Achieving this level of characterization requires techniques that can correlate catalytic performances to specific surface structures, so as to avoid averaging effects. Tip-enhanced Raman spectroscopy combines scanning probe microscopy with plasmon-enhanced Raman scattering and provides simultaneous topographical and chemical information at the nano/atomic scale from ambient to ultrahigh-vacuum and electrochemical environments. Therefore, it has been used to monitor catalytic reactions and is proposed to correlate the local structure and function of heterogeneous catalysts. Bimetallic catalysts, such as Pd–Au, show superior performance in various catalytic reactions, but it has remained challenging to correlate structure and reactivity because of their structural complexity. Here, we show that TERS can chemically and spatially probe the site-specific chemical (electronic and catalytic) and physical (plasmonic) properties of an atomically well-defined Pd(sub-monolayer)/Au(111) bimetallic model catalyst at 3 nm resolution in real space using phenyl isocyanide as a probe molecule (Fig. 1a). We observe a weakene...
Source: Nature Nanotechnology - Category: Nanotechnology Authors: Tags: Letter Source Type: research