Wednesday, 30 July 2014
Advanced search

Nanomaterial withstands 850ºC

University of Pittsburgh researchers have developed a composite nanomaterial that is stable at high temperatures.

Götz Veser, an associate professor of chemical and petroleum engineering in the University of Pittsburgh’s Swanson School of Engineering, and Anmin Cao created the 4nm-sized metal-alloy particles of platinum and rhodium that could withstand temperatures of more than 850oC, at least 250 degrees more than typical metallic nanoparticles.

Previous attempts to stabilise the metals have involved encasing them in heat-resistant nanostructures, but the most promising methods only produced particles in the 10nm to 15nm range.

To make their nanoparticles, the researchers created a blend of platinum and rhodium, which has a high melting point. They tested the alloy via a methane combustion reaction and found that the composite was not only a highly reactive catalyst, but that the particles maintained an average size of 4.3nm even during extended exposure at 850oC.

Small amounts of the 4nm particles remained after the temperature topped 950oC, although the majority had increased to eight times that size.

Veser and Cao discovered that the alloy sacrificed the low-tolerance platinum at high temperatures, then reconstituted itself as a rhodium-rich catalyst to finish the reaction. At around 700oC, the platinum-rhodium alloy began to melt. The platinum then ‘bled’ from the particle and formed larger particles with other errant platinum, leaving the more durable alloyed particles.

Veser and Cao predict that this self-stabilisation would occur for all metal catalysts alloyed with a second, more durable metal.

Veser and Cao conducted their work with support from the National Energy Technology Laboratory, the lead research and development office for the US Department of Energy’s (DOE) Office of Fossil Energy, as well as the DOE’s Office of Basic Energy Sciences and the National Science Foundation.

Have your say


My saved stories (Empty)

You have no saved stories

Save this article

Digital Edition

The Engineer July Digi Issue


London Mayor Boris Johnson is lobbying for a £10 additional charge for diesel cars to drive into Central London by 2020, and for road tax on diesel cars and all pre-2006 cars to be increased, to counter air pollution. What option most closely matches your opinion on this?

Previous Poll

Europe's largest tidal array in the Pentand Firth off Orkney will eventually generate up to 86MW of power. What will it take for tidal energy to make an appreciable contribution to the UK's energy needs?

Read and comment on the results here