Preparation and structure of a single Au atom on the TiO2(110) surface: control of the Au–metal oxide surface interaction

Asakura, Kiyotaka; Takakusagi, Satoru; Ariga, Hiroko; Chun, Wang‐Jae; Suzuki, Shuichi; Koike, Yuichiro; Uehara, Hiroki; Miyazaki, Kei; Iwasawa, Yasuhiro

doi:10.1039/c2fd20131c

Cited by 22 publications

(18 citation statements)

References 46 publications

(77 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another remedy is to combine the m-RMC with the polarization dependent XAFS analysis. As mentioned in introduction, polarization dependent XAFS can be obtained from metal species on the single crystal oxide surface which determined the bond angle and 3 D structure [53][54][55][56][57]. The m-RMC method will provide the distributions of the bond angle.…”

Section: What Kind Of Information Do We Derive From the M-rmc?mentioning

confidence: 99%

Micro Reverse Monte Carlo Approach to EXAFS Analysis

Fujikawa

Ariga

Takakusagi

et al. 2014

e-J. Surf. Sci. Nanotechnol.

Self Cite

View full text Add to dashboard Cite

We have developed a new Reverse Monte Carlo code, called the micro Reverse Monte Carlo (m-RMC), which is applicable to structure analysis of nanomaterials and surface species. In the m-RMC, Reverse Monte Carlo is applied to an ensemble of replica files, each of which contains one molecule or one small cluster, because the Extended X-ray Absorption Fine Structure (EXAFS) is sensitive to short-range structures and has negligible interaction between molecules or clusters. We apply the m-RMC to face-centered cubic metals (Cu, Pd, and Pt) and discuss the advantages, validation, and problems of the m-RMC. The bond distance and some cumulant coefficients can be determined from the EXAFS using m-RMC. Some 50-100 replica files are sufficient to reproduce the EXAFS oscillations and radial distributions. The bond distance can be determined, including the asymmetric distributions, by m-RMC. We also apply m-RMC to α-MoO3 and Au clusters. The m-RMC analysis of MoO3 shows that three radial distribution peaks appear corresponding to three types of MoO bonds. The m-RMC analysis of Au cluster indicates the presence of Au55 cuboctahedral structure with Au-Au distance at 0.288 nm. We obtain a 3 D image of Au55 nanocluster from the unified file. The m-RMC method can be applied to the analysis of the EXAFS for chemical systems with appropriate care.

show abstract

Section: What Kind Of Information Do We Derive From the M-rmc?mentioning

confidence: 99%

Micro Reverse Monte Carlo Approach to EXAFS Analysis

Fujikawa

Ariga

Takakusagi

et al. 2014

e-J. Surf. Sci. Nanotechnol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the curve fitting analysis of the PTRF‐XAFS spectra for Au/ o ‐MBA/TiO 2 (110) (Au coverage: 0.1 ML), no contribution from Au−Au interaction was detected, whereas Au−S (0.232±0.003 nm) and Au−O (0.210±0.003 nm) interactions were dominant in all three orientations (

\overset{E}{true}

([], 001)

, [

1 \overline{1} 0

] and

([], 110)

) . Figure shows the 3D model structure obtained by the FEFF simulation.…”

Section: Ultra‐high Dispersion Of Metals On Tio2(110) Premodified Witmentioning

confidence: 83%

“…In contrast, if the oxide support surface is premodified using an organic ligand that strongly anchors metal atoms to the surface through covalent bonds, then attachment of ultra‐highly dispersed metal species such as monatomic metal species can be expected without the need for organometallic compounds. We have successfully prepared atomically dispersed metals (single metal dispersion) with this technique on the basis of metal‐ligand bonding, simply by vacuum deposition of metal atoms onto an oxide single‐crystal surface premodified with a functional organic molecule (Figure ), and their 3D structures were precisely determined using the PTRF‐XAFS technique . For example, when ortho ‐mercaptobenzoic acid ( o ‐MBA) is used as the premodification molecule, monatomic Cu, Au and Ni atoms are energetically stabilized on the TiO 2 (110) surface by the formation of bonds with sulfur of the adsorbed o ‐MBA and the bridging oxygen in the TiO 2 lattice, whereas aggregation of the metal atoms occurs easily in the absence of o ‐MBA.…”

Section: Introductionmentioning

confidence: 99%

Premodified Surface Method to Obtain Ultra‐Highly Dispersed Metals and their 3D Structure Control on an Oxide Single‐Crystal Surface

Takakusagi

Iwasawa

Asakura

2018

The Chemical Record

Self Cite

View full text Add to dashboard Cite

Precise control of the three-dimensional (3D) structure of highly dispersed metal species such as metal complexes and clusters attached to an oxide surface has been important for the development of next-generation high-performance heterogeneous catalysts. However, this is not easily achieved for the following reasons. (1) Metal species are easily aggregated on an oxide surface, which makes it difficult to control their size and orientation definitely. (2) Determination of the 3D structure of the metal species on an oxide powder surface is hardly possible. To overcome these difficulties, we have developed the premodified surface method, where prior to metal deposition, the oxide surface is premodified with a functional organic molecule that can strongly coordinate to a metal atom. This method has successfully provided a single metal dispersion on an oxide single-crystal surface with the 3D structure precisely determined by polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS). Here we describe our recent results on ultra-high dispersions of various metal atoms on TiO (110) surfaces premodified with mercapto compounds, and show the possibility of fine tuning and orientation control of the surface metal 3D structures.

show abstract

“…The study of the stability of Au n on anatase TiO 2 (110) surface carried out by Pabisiak et al [22] showed that the finite linear Au n clusters will be formed on the highly defected surface. Asakura [23] found that Au anion is very important for the stability of Au n adsorbed on TiO 2 (110) surface. At the same time, Li et al [24] explored the influence of Au n /TiO 2 on CO oxidation and showed that the reaction rate is dependent on the size and shape of the Au n .…”

Section: Introductionmentioning

confidence: 99%

Influences of MgO(001) and TiO2(101) Supports on the Structures and Properties of Au Nanoclusters

et al. 2019

View full text Add to dashboard Cite

Due to the unique structures, photoelectric properties, good catalytic activity, and broad potential applications, gold nanoclusters (Au n ) received extensive attention in catalysis, bioengineering, environmental engineering, and so on. In the present work, the structures and properties of Au n adsorbed on the MgO(001) and TiO 2 (101) surfaces were investigated by density functional theory. The results showed that the catalytic properties of Au n will be enhanced when Au n is adsorbed on certain supports. Because the difference of the outer electronic structure of metals in supports, the direction of the charge transfer was different, thus inducing the different charge distribution on Au n . When Au n was adsorbed on MgO(001) [TiO 2 (101)] surface, Au n will have negative [positive] charges and thus higher catalytic activity in oxidation [reduction] reaction. The variation of surface charges caused by the support makes Au n possess different catalytic activity in different systems. Moreover, the electronic structure of the support will make an obvious influence on the s and d density of states of Au n , which should be the intrinsic reason that induces the variations of its structure and properties. These results should be an important theoretical reference for designing Au n as the photocatalyst applied to the different oxidation and reduction reactions.

show abstract

Preparation and structure of a single Au atom on the TiO2(110) surface: control of the Au–metal oxide surface interaction

Cited by 22 publications

References 46 publications

Micro Reverse Monte Carlo Approach to EXAFS Analysis

Micro Reverse Monte Carlo Approach to EXAFS Analysis

Premodified Surface Method to Obtain Ultra‐Highly Dispersed Metals and their 3D Structure Control on an Oxide Single‐Crystal Surface

Influences of MgO(001) and TiO2(101) Supports on the Structures and Properties of Au Nanoclusters

Contact Info

Product

Resources

About