A two-dimensional alloy material, made from five metals as opposed to the traditional two, has been developed by a collaboration between researchers at the McKelvey School of Engineering at Washington University in St. Louis and researchers at the College of Engineering at the University of Illinois at Chicago. The research, from the lab of Rohan Mishra, assistant professor in the Department of Mechanical Engineering & Materials Science at Washington University, was published in the journal Advanced Materials.
“We’re looking at transforming carbon dioxide, which is a greenhouse gas, into carbon monoxide,” Mishra said. “Carbon monoxide can be combined with hydrogen to make methanol. It could be a way to take CO2 from the air and recycle it back into a hydrocarbon.”
The basis of this innovation is a class of materials known as transition metal dichalcogenides (TMDCs) — they include transition metals and a chalcogen, which includes sulfur, selenium, and tellurium. When an alloy contains more than three metals at near equal ratios, it’s said to be “high entropy.” Hence the wordy name of the material developed in Mishra’s lab: high-entropy transition metal dichalcogenides.
TMDCs are not new. There has been interest in similar two-dimensional forms of these materials due to their unique optical and electronic properties, Mishra said. But he had a suspicion they could be used for something else. With 10 applicable transition metals and three chalcogens, there are 135 two-metal and 756 five-metal possible TMDC alloys. However, just like oil and water, not all combinations will mix together to form a homogenous alloy.
The work stems from a DMREF grant from the National Science Foundation as part of the Materials Genome Initiative launched by President Barack Obama in 2011 as a multi-agency initiative to create policy, resources, and infrastructure that support U.S. institutions to discover, manufacture and deploy advanced materials efficiently and cost-effectively.
For more information: Washington University in St. Louis
