Strong metal-support interaction structure

The structure of supported rhodium catalysts has been the subject of intensive research during the last decade. Rhodium is the component of the automotive exhaust catalyst (the three-way catalyst) responsible for the reduction of NO by CO [1], In addition, it exhibits a number of fundamentally interesting phenomena, such as strong metal-support interaction after high temperature treatment in hydrogen [21, and particle disintegration under carbon monoxide [3]. In this section we illustrate how techniques such as XPS, STMS, EXAFS, TEM and infrared spectroscopy have led to a fairly detailed understanding of supported rhodium catalysts. 

The crystalline structure of the metal is also affected by the metal-support interaction. Metal particles supported on CNFs have a highly crystalline structure due to strong metal-support interaction [155], whereas Pt particles supported on Vulcan and OMCs have a more dense globular morphology due to weak metal-support... 

Strong metal-support interactions (SMSI) and electronic structures In situ atomic resolution ETEM... 

Our intention was to employ the reaction of neopentane for probing the Pd surface, especially when the so-called strong metal-support interactions were expected. Such interactions may be manifested both in topographical (sintering and pillbox structure) as well as in chemical changes (decoration by support species and formation of an intermetallic compound) of the surface of Pd particles, and it would be difficult to decide a priori to what extent each of these factors may contribute to the observed changes in the catalytic behavior. Our goal was to try to separate these two factors. 

Bowker M, Stone P, Morrall P, et al. Model catalyst studies of the strong metal-support interaction surface structure identified by STM on Pd nanoparticles on TiO2(110). J Catal. 2005 234 172-81. 

Abbreviations BCC. body centered cubic DOS. density of states ESR. electron spin resonance HX.AI S, extended X-ray absorption fine structure F CC. face centered cubic (a crystal structure). FID, free induction decay FT, Fourier transform FWHM, full width at half maximum HCP, hexagonal close packed HOMO, highest occupied molecular orbital IR, Infrared or infrared spectroscopy LDOS, local density of states LUMO, lowest unoccupied molecular orbital MAS. magic angle spinning NMR. nuclear magnetic resonance PVP. poly(vinyl pyrrolidone) RF. Radiofrequency RT, room temperature SEDOR, spin echo double resonance Sf, sedor fraction SMSI, strong metal-support interaction TEM. transmission electron microscopy TOSS, total suppression of sidebands. 

Jennison DR, Dulub O, Hebenstreit W, Diebold U (2001) Structure of an ultrathin TiO film, formed by the strong metal support interaction (SMSI), on Pt nanocrystals on UO ll 10). Surf Sci 492 L677... 

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