(CN) — Researchers have found a way to reduce platinum use for industrial purposes by combining it with gallium — a metal that can melt in a warm room — to spark chemical reactions at a much lower temperature and increased efficiency, paving the way for lower emissions in many industries.
Australian scientists at the University of New South Wales Sydney and RMIT University published a study in the journal Nature Chemistry on Monday that demonstrated how impregnating liquid gallium with trace amounts of liquid platinum allowed them to heat the metals at high temperatures for a shorter amount of time, then reduce the temperature to more efficient levels for sustained periods while the liquid alloy facilitated chemical reactions.
“To keep the single atoms separated from each other, the conventional systems require solid matrices (such as graphene or metal oxide) to stabilize them,” lead author Md. Arifur Rahim of UNSW Sydney said in a statement. “I thought, why not [use] a liquid metal matrix instead and see what happens.”
Though platinum is an effective catalyst for chemical reactions, most manufacturers have shied away from the metal due to its extreme melting point of 1,700 degrees Celsius, or more than 3,000 degrees Fahrenheit. Manufacturers would have to maintain these high temperatures to keep the platinum in a liquid state, which has high operating costs in industries such as ammonia refining and fertilizer production, according to the study.
The new process is more than 1,000 times more efficient by using a ratio of less than 0.0001 platinum to gallium in suspension and eliminates clogging problems in the process, “self-regulating its effectiveness over a long period of time and avoiding the catalytic equivalent of pond scum building on the surface,” according to the peer-reviewed article.
The discovery could extend the planet's reserves of valuable platinum and offer more sustainability solutions for reducing carbon dioxide emissions.
Researchers also learned that the platinum does not return to a solid state “right down to the level of individual atoms” in this new process, even as they reduced temperatures. Additionally, gallium proved to be an effective medium as a suspension matrix for the platinum.
The team used advanced computer modeling to map the atomic movements during their experiments and discovered an important factor as to why liquid gallium was such an effective element in the process.
“What we found is the two platinum atoms never came into contact with each other,” Nastaran Meftahi, a research fellow at the ARC Centre of Excellence in Exciton Science, said in a statement. “That’s really cool and it’s what we found with the modeling, which is very difficult to observe directly through experiments.”
Though most importantly to scientists, the reactions that they wanted to cause were not possible without platinum present in the gallium.
“The platinum is actually a little bit below the surface and it’s activating the gallium atoms around it,” Dr. Andrew Christofferson, Exciton Science associate investigator, said. “So the magic is happening on the gallium under the influence of platinum.”