Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Mar 31;21(4):432.
doi: 10.3390/molecules21040432.

On the High Sensitivity of the Electronic States of 1 nm Gold Particles to Pretreatments and Modifiers

Oxana Martynyuk  1   2 , Yulia Kotolevich  3 , Rodrigo Vélez  4 , Jesus Efren Cabrera Ortega  5 , Hugo Tiznado  6 , Trino Zepeda Partida  7 , Josué D Mota-Morales  8 , Alexey Pestryakov  9 , Nina Bogdanchikova  10
Affiliations

On the High Sensitivity of the Electronic States of 1 nm Gold Particles to Pretreatments and Modifiers

Oxana Martynyuk et al. Molecules. .

Abstract

In this paper, the effect of modifiers and pretreatments on the electronic states of 1 nm gold nanoparticles (AuNPs) supported on silica was systematically studied. AuNPs deposited on silica (particle size of 2-4 nm) modified with Ce, La and Fe oxides, were studied by FTIR of adsorbed CO after different redox treatments at 100, 300 and 500 °C. This study was conducted at room temperature to allow detecting the electronic states of gold, which is more likely involved in CO oxidation at the same temperature. AuNP size distribution was measured by HRTEM. It is shown that the electronic state of gold species (Aun(δ-), Au⁰, Aun(δ+), Au⁺) in 1 nm AuNPs is sensitive to the modifier as well as to the temperatures of redox pretreatments. Supports modified with the same additives but containing larger AuNPs (~3, 4, 5, and 7 nm) were also studied. They showed that Au⁰ remains stable irrespective of additives and redox pretreatments, indicating no significant effect of such treatments on the electronic properties of larger AuNPs. Samples with a predominant AuNP size of 2 nm are an intermediate case between these two groups of materials.

Keywords: 1 nm gold; FTIR CO; electron stage of gold; sensitivity to pretreatment.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Au particle size distribution obtained by HRTEM: Au/La/SiO2-s (a); Au/La/SiO2-i (b); Au/Fe/SiO2-s (c); Au/Fe/SiO2-i (d); Au/Ce/SiO2-s (e); Au/SiO2 (f).
Figure 2
Figure 2
FTIR spectra of CO adsorbed on Au/La/SiO2-s (a); Au/La/SiO2-i (b); Au/Fe/SiO2-s (c); Au/Fe/SiO2-i (d); Au/Ce/SiO2-s (e); Au/ SiO2 (f) after different treatments.
Figure 3
Figure 3
Au particle size distribution obtained by TEM for Au/TiO2 (a); Au/La/TiO2-i (b); Au/Mg/TiO2-i (c); Au/Fe/TiO2-i (d); Au/Ce/TiO2-i (e).
Figure 3
Figure 3
Au particle size distribution obtained by TEM for Au/TiO2 (a); Au/La/TiO2-i (b); Au/Mg/TiO2-i (c); Au/Fe/TiO2-i (d); Au/Ce/TiO2-i (e).
Figure 4
Figure 4
FTIR spectra of CO adsorbed on for Au/TiO2 (a); Au/La/TiO2-i (b); Au/Mg/TiO2-i (c); Au/Fe/TiO2-i (d); Au/Ce/TiO2-i (e).
See this image and copyright information in PMC

References

    1. Laguna O.H., Romero Sarria F., Centeno M.A., Odriozola J.A. Gold supported on metal-doped ceria catalysts (M = Zr, Zn and Fe) for the preferential oxidation of CO (PROX) J. Catal. 2010;276:360–370. doi: 10.1016/j.jcat.2010.09.027. - DOI
    1. Gonzalez Castaño M., Reina T.R., Ivanova S., Centeno M.A., Odriozola J.A. Pt vs. Au in water–gas shift reaction. J. Catal. 2014;314:1–9. doi: 10.1016/j.jcat.2014.03.014. - DOI
    1. Tuzovskaya I., Lima E., Bosch P., Bogdanchikova N., Pestryakov A., Fraissard J. Influence of cation nature on stabilization of gold nanospecies in mordenites. J. Nanosci. Nanotechnol. 2011;11:5469–5475. doi: 10.1166/jnn.2011.3432. - DOI - PubMed
    1. Riahi G., Guillemot D., Polisset-Thfoin M., Khodadadi A.A., Fraissard J. Preparation, characterization and catalytic activity of gold-based nanoparticles on HY zeolites. Catal. Today. 2002;72:115–121. doi: 10.1016/S0920-5861(01)00485-0. - DOI
    1. Arrii S., Morfin F., Renouprez A.J., Rousset J.L. Oxidation of CO on Gold supported catalysts prepared by laser vaporization: Direct evidence of support contribution. J. Am. Chem. Soc. 2004;126:1199–1205. doi: 10.1021/ja036352y. - DOI - PubMed

Publication types

LinkOut - more resources