U.S. scientists say they've come up with new, cheaper way of converting waste carbon dioxide into a precursor element of gasoline or other fuels.
The new technique brings the procedure closer to being commercially viable, say researchers at the University of Illinois, by reducing the number of steps in the process and by replacing expensive gold or silver used in the reduction reaction with a cheaper metal to create synthesis gas, or syngas, a precursor compound.
Engineering Professor Amin Salehi-Khojin and colleagues have developed a catalytic process based on molybdenum disulfide and an ionic liquid to reduce carbon dioxide to syngas.
The results of their studies have been reported in Nature Communications.
"With this catalyst, we can directly reduce carbon dioxide to syngas without the need for a secondary, expensive gasification process," says UI researcher Mohammad Asadi, a graduate student and study co-author.
Molybdenum disulfide has proved an ideal catalyst to drive the reduction of the reduction of the carbon dioxide, as per Salehi-Khojin.
"This is a very generous material," he says. "We are able to produce a very stable reaction that can go on for hours."
In other systems using chemical reduction, carbon monoxide is the only product of the reaction, while the new catalyst creates syngas, a mixture of hydrogen and carbon monoxide.
The new catalyst allows for easy manipulation of the proportions or carbon monoxide and hydrogen in the syngas produced, the researchers said.
In addition, it requires very little work to get a sustainable catalytic reaction going, they said.
"In comparison with other two-dimensional materials like graphene, there is no need to play with the chemistry of molybdenum disulfide, or insert any host materials to get catalytic activity," says researcher and study co-author Bijandra Kumar.
The ability to use an inexpensive material like molybdenum disulfide rather than more expensive material moved the technology much close to industrialization, the researchers say.
"Our whole purpose is to move from laboratory experiments to real-world applications. This is a real breakthrough that can take a waste gas -- carbon dioxide -- and use inexpensive catalysts to produce another source of energy at large-scale, while making a healthier environment," they say.
Syngas gets its name from an intermediate use in the production of synthetic natural gas or synthetic petroleum. It is also used in the production of methanol or ammonia.
