Researchers at the University of Minnesota have invented a ‘catalytic condenser’ that can electronically modify one metal to behave like another, such as giving aluminum the catalytic properties of tungsten. Image: Dauenhauer Group, University of Minnesota.
Researchers at the University of Minnesota have invented a ‘catalytic condenser’ that can electronically modify one metal to behave like another, such as giving aluminum the catalytic properties of tungsten. Image: Dauenhauer Group, University of Minnesota.

A team led by researchers at the University of Minnesota Twin Cities has invented a ground-breaking device that can electronically modify one metal into behaving like another for use as a catalyst for speeding chemical reactions. The fabricated device, called a ‘catalytic condenser’, is the first to demonstrate that electronically modifying materials to provide new properties can lead to faster, more efficient chemical processing.

This invention opens the door to new catalytic technologies that use non-precious-metal catalysts for important applications such as storing renewable energy, making renewable fuels and manufacturing sustainable materials. The team reports the invention in a paper in JACS Au; it is also working with the University of Minnesota Office of Technology Commercialization and has a provisional patent on the device.

For the past century, chemical processing has relied on the use of specific catalytic materials to promote the manufacturing of chemicals and materials. Many of these materials, such as the precious metals ruthenium, platinum, rhodium and palladium, have unique electronic surface properties. They can act as both metals and metal oxides, making them critical for controlling chemical reactions. But these expensive materials are often in short supply around the world and have become a major barrier to advancing technology.

In order to develop a method for tuning the catalytic properties of alternative materials, the researchers relied on their knowledge of how electrons behave at surfaces. The team successfully tested a theory that adding electrons to or removing them from a specific metal oxide can turn it into something that mimicked the properties of another metal.

“Atoms really do not want to change their number of electrons, but we invented the catalytic condenser device that allows us to tune the number of electrons at the surface of the catalyst,” said Paul Dauenhauer, professor of chemical engineering and materials science at the University of Minnesota, who led the research team. “This opens up an entirely new opportunity for controlling chemistry and making abundant materials act like precious materials.”

The catalytic condenser device uses a combination of nanometer films to move and stabilize electrons at the surface of the catalyst material. This design combines metals and metal oxides with graphene to enable fast electron flow with surfaces that are tunable for chemistry.

“Using various thin-film technologies, we combined a nanoscale film of alumina made from low-cost abundant aluminum metal with graphene, which we were then able to tune to take on the properties of other materials,” said Tzia Ming Onn, a post-doctoral researcher at the University of Minnesota, who fabricated and tested the catalytic condensers. “The substantial ability to tune the catalytic and electronic properties of the catalyst exceeded our expectations.”

The catalytic condenser design has broad utility as a platform device for a range of manufacturing applications. This versatility comes from its nanometer fabrication, which incorporates graphene as an enabling component of the active surface layer. The power of the device to stabilize electrons (or the absence of electrons, known as ‘holes’) is tunable by varying the composition of a strongly insulating internal layer. The device’s active layer can also incorporate base catalyst materials with additional additives, which can then be tuned to achieve the properties of expensive catalytic materials.

“We view the catalytic condenser as a platform technology that can be implemented across a host of manufacturing applications,” said Dan Frisbie, professor and head of the University of Minnesota Department of Chemical Engineering and Materials Science, and research team member. “The core design insights and novel components can be modified to almost any chemistry we can imagine.”

The team plans to continue its research on the catalytic condenser by applying it to precious metals for some of the most important sustainability and environmental problems. With financial support from the US Department of Energy and the US National Science Foundation, several parallel projects are already in progress to store renewable electricity as ammonia, manufacture the key molecules in renewable plastics and clean gaseous waste streams.

This story is adapted from material from the University of Minnesota, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.