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In the battle against climate change, researchers are looking for ways to convert carbon dioxide (CO₂) into useful products. They're studying nano-sized materials called catalysts that can accelerate the conversion process or make it more efficient. Nanomaterials are magnitudes smaller than the width of a human hair.

Many catalysts rely on precious metals such as platinum, gold, and silver, which are costly and not readily available. While scientists are trying to develop new catalysts that use cheaper alternatives, such as nickel, nitrogen, and carbon, these options are not quite as efficient.

Researchers from McMaster University in Ontario have come up with a new formula that adds tiny particles of a material called nickel zinc carbide to a type of nickel-nitrogen-carbon catalysts under development in their laboratory.

They found the resulting catalyst was very efficient in converting CO₂ to carbon monoxide, an important ingredient in many chemical processes used in industry—including the production of methanol. The work is in the journal ACS Electrochemistry.

"We wanted to develop a new catalyst that is stable, very active, and also relies on metals and materials that are relatively abundant," says Dr. Drew Higgins, lead researcher on project.

In their McMaster lab, Higgins and his team determined the new catalyst was very efficient at converting CO₂ to CO, but that analysis couldn't explain why it worked so well. So, the Ph.D. student leading the project, Fatma Ismail, brought their samples to the Canadian Light Source (CLS) at the University of Saskatchewan.

"The types of materials that we're looking at are relatively new, so we really didn't understand how they perform," says Higgins, an associate professor in McMaster's Department of Chemical Engineering. "The ultrabright X-rays at the CLS enabled us to see their structures and properties, which helps explain how they perform."

Higgins says he and his colleagues were pleasantly surprised by how well the combination of materials performed. The insights they gained about the specific role nickel was playing in the reaction would not have been possible without the HXMA beamline, he says.

Their next step will be incorporating the material into prototype devices. "Once we can demonstrate that this (catalyst) works effectively then we can start to scale up the systems," says Higgins. "We can make these systems much larger so that they can convert much more CO₂ and then eventually—ideally—one day we can translate that so industrial companies that have large CO₂ emissions could plug this into their smokestack and remove the emissions before it goes into the atmosphere—and convert it into something that has value and has use in society."