Carbon dioxide accounts for over 80 percent of all greenhouse gas emissions. For many, carbon dioxide emissions account for significant environmental issues, but for researchers like Haotian Wang of Harvard University, carbon dioxide could be the perfect raw material.
According to a new study, Wang and his team are well on the way to developing a system that uses renewable electricity to electrochemically transform carbon dioxide into carbon monoxide. The carbon monoxide could then be used in a host of industrial processes, such as plastics production, creating hydrocarbon products, or as a fuel itself.
This from Harvard University:
The energy conversion efficiency from sunlight to CO can be as high as 12.7%, more than one order of magnitude higher than natural photosynthesis.
“Basically, what this is is a form of artificial photosynthesis,” Wang said. “In a plant, sunlight, CO2 and water become sugar and oxygen. In our system, the input is sunlight, CO2 and water, and we produce CO and oxygen.”
Through the process, a catalyst binds freed protons and carbon dioxide molecules, crating water and carbon monoxide. However, the challenge has been finding a catalyst that does not produce hydrogen gas and is not made of precious metals, such as gold and silver, which would make scaling this project extremely costly.
To solve this problem, Wang called on Stanford University collaborators and ECS members, Yi Cui and Jens Nørskov.
Yi Cui and Jens Nørskov, set about working to “tune” the electronic properties of the metals. Samira Siahrostami, a staff scientist from Nørskov group rationalized the nature of active sites by atomic scale modeling and discovered that dispersing nickel metals into isolated single atoms, which are trapped in graphene vacancies, produced a material that was eager to react with carbon dioxide and willing to release the resulting carbon monoxide.
The ultimate goal of the research is to one day be able to scale this technology up to a level where it could scrub carbon dioxide from the atmosphere.
“The basic idea was if we can capture existing CO2 and use renewable electricity, from solar or wind power, to reduce it into useful chemicals,” Wang said, “then we can possibly form a carbon loop.”