Researchers including the University of Tokyo have discovered for the first time a way to improve the durability of gold catalysts by creating a protective layer of metal oxide clusters. Enhanced gold catalysts can withstand physical environments over a greater time range than their unprotected counterparts. This can increase the range of possible applications and in some cases reduce energy consumption and costs. These catalysts are widely used in industrial fields such as chemical synthesis and pharmaceutical production, all of which can benefit from improved gold catalysts.
Everyone loves gold: athletes, pirates, bankers - everyone. Historically, gold has been an attractive metal, used to make medals, jewelry, coins, and more.
What makes gold so shiny and alluring is its chemical properties that resist physical conditions where other materials can fade, such as heat, pressure, oxidation and other harmful substances.
Paradoxically, however, at the nanoscale, tiny gold particles buck this trend and become so active that they have long been key to realizing a variety of catalysts, intermediate substances that speed up or somehow make chemical reactions happen. In other words, they are useful or necessary substances for converting one substance into another, and therefore are widely used in synthesis and manufacturing.
The innovation behind enhanced gold catalysts
Kosuke Suzuki, associate professor at the Department of Applied Chemistry at the University of Tokyo, said: "Gold is a magical metal that is rightly praised in society, especially in the scientific field. Gold is an ideal material for catalysts and can help us synthesize various substances including drugs. Reasons Because gold has a low affinity for absorbing molecules and is highly selective for the substances it binds to, it allows very precise control of the chemical synthesis process. Gold catalysts typically operate at lower temperatures and pressures, require less energy, and have less of an environmental impact than traditional catalysts."
As good as gold is, it has some drawbacks. The smaller the gold particles, the more reactive it is, and at some point, catalysts made with gold begin to be negatively affected by heat, pressure, corrosion, oxidation and other conditions. Suzuki and his team thought they could improve the situation and designed a new protectant that would allow gold catalysts to maintain their useful functionality over a wider range of physical conditions that would normally hinder or destroy typical gold catalysts.
"The gold nanoparticles currently used in catalysts have a certain degree of protection, thanks to agents such as dodecanethiol and organic polymers. But our new technology is based on a type of metal oxide cluster called polyoxymetal salt, which is much more effective, especially when it comes to oxidative stress," Suzuki said.
"We are currently investigating novel structures and applications of polyoxymetalates. This time we applied polyoxymetalates to gold nanoparticles and determined that polyoxymetalates improved the durability of the nanoparticles. The real challenge lies in applying various analytical techniques to test and verify this."
The research team used a variety of techniques collectively known as spectroscopy. They used no fewer than six spectroscopic methods, which varied in the kinds of information they revealed about matter and its behavior. But generally speaking, they work by projecting some kind of light onto a substance and then using specialized sensors to measure how the light changes in some way. Suzuki and his team spent several months running various tests and different configurations of their experimental materials until they found what they were looking for.
"Our goal is not just to improve certain chemical synthesis methods," Suzuki said. "Our enhanced gold nanoparticles have many applications that could benefit society: catalysts that break down pollution (many gasoline cars already have the familiar catalytic converters), low-impact pesticides, green chemistry for renewable energy, medical interventions, food sources Sexual pathogen sensors, and the list goes on. But we want to go even further. The next steps will be to improve the range of physical conditions to make the gold nanoparticles more adaptable, and also to look at how to add some durability to other useful catalytic metals such as ruthenium, rhodium, rhenium and, of course, something more popular than gold: platinum."
Compiled source: ScitechDaily