Chameleon” metal could lead to new catalytic technologiesEnergy researchers have fabricated a new device called a “catalytic condenser” that can electronically convert one metal into behaving like another to use as a catalyst for speeding up chemical reactions. Such “chameleon” metal could lead to new catalytic technologies based on non-precious metal catalysts and help improve the efficiency for storing renewable energy, producing carbon-free fuels, as well as making sustainable materials.
The study, led by a team from the University of Minnesota Twin Cities, showed for the first time that alternative materials that are electronically modified to provide new properties can yield faster and more efficient chemical processing. The device is based on a combination of nanometer films to move and stabilize electrons at the surface of the catalyst. It uses a mechanism of combining metals and metal oxides with graphene to enable fast electron flow with surfaces that are tunable for chemistry.
As described in JACS Au [Ming Onn et al. JACS Au (2022) DOI: 10.1021/jacsau.2c00114], the invention allows electronic modulation of a metal catalyst with time. It works by either adding or removing electrons from a metal surface. On stabilizing a metal with unbalanced electrons, it takes on the properties of other metals for surface chemistry. Although the metal retains its identity, the modulated surface in the catalytic condenser behaves like a more expensive metal.
Chemical processing usually depends on precious metals such as ruthenium, platinum, rhodium and palladium. Although they have unique electronic surface properties that allow them to act as both metals and metal oxides, making them critical for controlling chemical reactions, they are in short supply globally and are expensive.
To test the device with various thin film technologies, a nano-scale film of alumina was combined with graphene as an enabling component of the active surface layer, which was then tuned to take on the properties of other materials. The team were surprised at how effectively the device modulated the behavior of catalytic materials to take on the property of other catalysts. As team leader Paul Dauenhauer told Materials Today, “Now we can use the catalytic condenser to tune in optimal performance of a catalyst just by turning a dial, and we can adjust that dial with immense precision. This is an entirely new way to design catalysts.”
The key application of catalysis is developing carbon-free fuels for energy storage, and if it is possible to convert solar and wind power to carbon-free fuels such as ammonia, then renewable energy can be stored and moved around as required. It is hoped the broad utility of the design will also serve as a platform device for numerous manufacturing applications. The next step is to understand the relationships between catalytic condenser design, applied charge strength, and the pattern of charge being applied to the catalyst surface.
“Now we can use the catalytic condenser to tune in optimal performance of a catalyst just by turning a dial, and we can adjust that dial with immense precision. This is an entirely new way to design catalysts.”Paul Dauenhauer