New information on binding gold particles over metal oxide surfaces

Jan 22, 2013
Figure Atomic structure.

The strong binding of gold on electronically modified calcium oxide can now be understood in detail. In a computational study, researchers at the University of Jyväskylä Nanoscience Center have shown how redox chemistry entirely determines the adsorption strength of gold on the modified oxide where one metal atom is replaced with molybdenum.

The research team applied the so-called Born-Haber cycle to analyse how different terms contribute to adsorption energy. The calculations were done at the supercomputers of the CSC – IT Center of Science by employing quantum mechanical simulation methods.

In the oxide lattice, the molybdenum atom donates two electrons into the oxide. When a gold atom adsorbs on the oxide surface, a redox reaction takes place. In this process, a third electron transferred by the dopant is gained by gold, and energy is released. By varying the dopant among several atoms, the researchers found that the amount of energy released linearly correlates with the ability of the dopant to give an electron. The trend can be used to estimate how much a guest atom stabilises gold adsorption without calculating the adsorption energy.

The research results are important for understanding catalyst-support interaction. The results fully support the where have been seen to form flat structures over modified surfaces. A similar Born-Haber cycle, as applied in this study, can also be employed to analyse oxide-catalysed chemical reactions that follow the redox mechanism.

Catalysts are commonly used by industry, for instance, in the production of fuels, plastics, fertilisers and other similar products. Metal oxide surfaces are widely used as support materials for particles. The binding properties and shape of metal nanoparticles sensitively depend on the interaction between the support and the catalyst. By tuning this interaction, it is possible to affect the number and properties of catalytically active sites, or even create new sites. One way to modify the interaction is to dope the oxide with guest that can donate extra electrons into a material.

Explore further: Substrates change nanoparticle reactivity

More information: Andersin, J. et al. The Redox Chemistry of Gold with High-Valence Doped Calcium Oxide, Angewandte Chemie International Edition, Article first published online: 12 DEC 2012, DOI: 10.1002/anie.201208443 . http://onlinelibrary.wiley.com/doi/10.1002/anie.201208443/abstract

Related Stories

The finest gold dust in the world

May 30, 2012

(Phys.org) -- Scientists at the Vienna University of Technology found a method to locate single gold atoms on a surface. This should pave the way to better and cheaper catalysts.

For clean air

Mar 30, 2007

In addition to nitrogen oxides and sulfur oxides, many volatile organic compounds (VOCs) in air contribute to smog and high ozone levels, as well as potentially damaging human health. Clean-air laws are thus rightly continuing ...

Recommended for you

Substrates change nanoparticle reactivity

3 hours ago

(Phys.org)—Nanoscale materials tend to behave differently than their bulk counterparts. While there are many theories as to why this happens, technological advances in scanning tunneling microscopy (STM) ...

Reviving cottonseed meals adhesives potential

5 hours ago

Cottonseed meal—the leftovers after lint and oil are extracted from cottonseed—is typically fed to ruminant livestock, such as cows, or used as fertilizer. But Agricultural Research Service scientists ...

New concrete composite can heal itself

6 hours ago

In the human body, small wounds are easily treated by the body itself, requiring no further care. For bigger wounds to be healed, the body may need outside assistance. Concrete is like a living body, in that ...

Actuators that mimic ice plants

6 hours ago

Engineers developing moveable robot components may soon take advantage of a trick plants use. Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam and Harvard University in Cambridge ...

Aromatic couple makes new chemical bonds

Jun 29, 2015

Esters have been identified to act as a new and clean coupling partner for the carbon-carbon bond forming cross-coupling reaction to make useful compounds for pharmaceuticals, agrochemicals and organic materials.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.