Researchers have created an unusual new alloy made up of not two, but five different metals, and put it to work as a catalyst. The new material is two-dimensional, and was able to convert carbon dioxide into carbon monoxide effectively, potentially helping to turn the greenhouse gas into fuels.
The new alloy belongs to a class of materials called transition metal dichalcogenides (TMDCs), which are, as the name suggests, made up of combinations of transition metals and chalcogens. Extremely thin films of TMDCs have recently shown promise in a range of electronic and optical devices, but researchers on the new study wondered if they could also be used as catalysts for chemical reactions.
The thinking goes that because reactions occur on the surface of a catalyst, materials with high surface areas will be more effective catalysts. And as sheets only a few atoms thick, TMDCs are almost nothing but surface area.
The team created computer models to sort through all the possible combinations of transition metals and chalcogens, and determine which ones would make the most effective catalysts. Eventually, they settled on one that contained an astonishing five transition metals – molybdenum, tungsten, vanadium, niobium and tantalum – along with sulfur as the chalcogen.
“The question was, ‘Could we even synthesize a TMDC alloy that had that many components?’” says John Cavin, an author of the study. “And will they improve the reduction of CO2 into CO?”
After picking the most promising candidate, the team then sent the data off to collaborators at the University of Illinois to synthesize the alloy. Not only was that successful, but in tests the material worked well at converting carbon dioxide into carbon monoxide, with a turnover frequency of 58.3 per second.
That means they could be useful for recycling the greenhouse gas into useable hydrocarbon fuels. The team says that this new alloy, as well as four others that showed some promise as catalysts, could have other uses that haven’t been explored yet.
“These are new materials, they have never before been synthesized,” says Rohan Mishra, lead author of the study. “They may have unanticipated properties.”
The research was published in the journal Advanced Materials.
