Effect of Size on Hydrogen Adsorption on the Surface of Deposited Gold Nanoparticles.

Andrey Gatin,Sergey Ozerin,Vasiliy Kharitonov,Nadezhda Dokhlikova,Boris Shub,Maxim Grishin,Sergey Sarvadii

doi:10.3390/nano9030344

Andrey Gatin, Sergey Ozerin + Show 5 more

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https://doi.org/10.3390/nano9030344

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Journal: Nanomaterials	Publication Date: Mar 3, 2019
Citations: 10	License type: CC BY 4.0

Affiliation: Russian Academy of Sciences

Abstract

An experimental study of molecular hydrogen adsorption on single gold nanoparticles of various sizes deposited on the surface of highly oriented pyrolytic graphite (HOPG) was carried out by means of scanning tunneling microscopy and spectroscopy. The effect of size on the HOPG/Au system was established. Hydrogen was dissociatively chemisorbed on the surface of gold nanoparticles with an average size of 5–6 nanometers. An increase in the size of nanoparticles to 10 nm or more led to hydrogen chemisorption being inhibited and unable to be detected.

Highlights

Gold is a perfect example of a material that is inert in its massive form and highly active in the nanoscale form
Gold nanoparticles are used in catalytic reactions of alkene hydrogenation [7], in chemoselective hydrogenation of crotonaldehyde to crotyl alcohol [8], in chemoselective hydrogenation of nitro compounds [9], and in heterogeneous hydroformylation of olefins [10]
With the use of calorimetry, transmission electron microscopy (TEM), and X-ray diffraction (XRD), direct synthesis of water from O2 and H2 was found to occur over silica-supported gold nanoparticles at 383–433 K and a pressure of the order of several kilopascals [16]

Summary

Introduction

Gold is a perfect example of a material that is inert in its massive form and highly active in the nanoscale form. The results obtained for Al2O3-supported gold nanoparticles [17,18] confirmed the conclusion of a previous report [16] about the interaction of gold and hydrogen. As shown by X-ray photoelectron spectroscopy (XPS) and mass spectroscopy in a previous report [19], hydrogen dissociation takes place on the perimeter interfaces between gold and TiO2 for a catalyst based on gold particles on a rutile TiO2 support. It has been stated that the sites of H2 dissociation must be low-coordinated gold atoms not directly bound to the stoichiometric and reduced TiO2 support. In a previous report [21], hydrogen atoms were suggested to be generated as a result of H2 dissociation on low-coordinated gold atoms with their further migration to the substrate

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