Preparation and Catalysis of Novel Colloidal Dispersions of Copper/Noble Metal Bimetallic Clusters

Langmuir ◽  
1994 ◽  
Vol 10 (12) ◽  
pp. 4574-4580 ◽  
Author(s):  
Naoki Toshima ◽  
Yuan Wang
Keyword(s):  
Noble Metal ◽  
Colloidal Dispersions ◽  
Bimetallic Clusters

scholarly journals Melting Behavior of Noble-Metal-Based Bimetallic Clusters

2009 ◽  
Vol 7 ◽  
pp. 149-156 ◽  
Author(s):  
Tsung-Wen Yen ◽  
P. J. Hsu ◽  
S. K. Lai
Keyword(s):  
Noble Metal ◽  
Melting Behavior ◽  
Bimetallic Clusters

Colloidal Dispersions of Palladium–Platinum Bimetallic Clusters Protected by Polymers. Preparation and Application to Catalysis

1989 ◽  
Vol 18 (10) ◽  
pp. 1769-1772 ◽  
Author(s):  
Naoki Toshima ◽  
Kakuta Kushihashi ◽  
Tetsu Yonezawa ◽  
Hidefumi Hirai
Keyword(s):  
Colloidal Dispersions ◽  
Bimetallic Clusters ◽  
Palladium Platinum

scholarly journals Gamma Radiolytic Formation of Alloyed Ag-Pt Nanocolloids

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
M. K. Temgire ◽  
Jayesh Bellare ◽  
S. S. Joshi
Keyword(s):  
Cluster Structure ◽  
Colloidal Dispersions ◽  
Bimetallic Clusters ◽  
Alloy Formation ◽  
Tem Analysis ◽  
Structural Formation ◽  
Gamma Radiolysis ◽  
Reduction Methods ◽  
Sequential Reduction ◽  
Brij 97

Colloidal dispersions of Ag-Pt composite nanoparticles were prepared by gamma radiolysis technique in the presence of nonionic surfactant Brij'97. Simultaneous as well as sequential reduction methods were employed in order to study the structural formation of Ag-Pt bimetallic clusters. Similar shape and trend was observed in optical spectra for both methods. Radiolysis yielded nearly spherical Ag-Pt bimetallic clusters by use of AgNO3 instead of AgClO4. The disappearance of the silver resonance and the simultaneous growth of the 260 nm resonance are independent of cluster structure and degree of alloying. To understand formation of Ag-Pt aggregate, the optical studies were also done as a function of amount of dose absorbed, concentration of surfactant, that is, Brij'97. The shape of the absorption spectrum did not change with increase in gamma radiation dose. TEM analysis exhibited fine dispersions of Ag-Pt clusters surrounded by a mantle when capped with Brij'97. The particle size obtained was in the range of 5–9 nm. On the basis of optical, XRD, and TEM analysis, alloy formation is discussed.

scholarly journals PdnAg(4−n) and PdnPt(4−n) clusters on MgO (100): a density functional surface genetic algorithm investigation

Nanoscale ◽  
2014 ◽  
Vol 6 (20) ◽  
pp. 11777-11788 ◽  
Author(s):  
Christopher J. Heard ◽  
Sven Heiles ◽  
Stefan Vajda ◽  
Roy L. Johnston
Keyword(s):  
Genetic Algorithm ◽  
Noble Metal ◽  
Density Functional ◽  
Global Optimisation ◽  
Bimetallic Clusters ◽  
Functional Surface ◽  
Mgo Substrate

Global optimisation of catalytically relevant noble metal mono and bimetallic clusters is performed directly on an MgO substrate with DFT. Charge is distributed locally upon the cluster, providing a means to atomically control binding and reaction sites, as found for CO molecules on Pd/Ag/Pt.

scholarly journals Modeling the Optical Responses of Noble Metal Nanoparticles Subjected to Physicochemical Transformations in Physiological Environments: Aggregation, Dissolution and Oxidation

2017 ◽  
Vol 231 (1) ◽  
Author(s):  
Jordi Piella ◽  
Neus G. Bastús ◽  
Víctor Puntes
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Biological Effects ◽  
Colloidal Dispersions ◽  
Noble Metal Nanoparticles ◽  
Full Width ◽  
Half Maximum ◽  
Biological Media ◽  
Optical Responses ◽  
Absorbance Curve

AbstractHerein, we study how optical properties of colloidal dispersions of noble metal nanoparticles (Au and Ag) are affected by processes such as aggregation and oxidative dissolution. The optical contributions of these processes to the extinction spectra in the UV-vis region are often overlapped, making difficult its interpretation. In this regard, modeling the UV-vis spectra (in particular absorbance curve, peaks position, intensity and full width at half maximum -FWHM) of each process separately offers a powerful tool to identify the transformation of NPs under relevant and complex scenarios, such as in biological media. The proper identification of these transformations is crucial to understand the biological effects of the NPs.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

Interlayer confinement synthesis of Ir nanodots/dual carbon as an electrocatalyst for overall water splitting

2020 ◽  
Author(s):  
Yaru Li ◽  
Yu-Quan Zhu ◽  
Weili Xin ◽  
Song Hong ◽  
Xiaoying Zhao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Noble Metal ◽  
High Efficiency ◽  
Overall Water Splitting ◽  
Highly Dispersed

Rationally designing low-content and high-efficiency noble metal nanodots offers opportunities to enhance electrocatalytic performances for water splitting. However, the preparation of highly dispersed nanodots electrocatalysts remains a challenge. Herein, we...

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