New Catalyst Uses Light to Convert Carbon Dioxide to Fuel

Researchers have found a new way to convert carbon dioxide into fuel.

Carbon emission into the atmosphere is set to hit a record high in 2019. And studies suggest that it’s not slowing any time soon.

Since the gas contributes to the warming climate, turning it into reusable fuel would be the holy grail of sustainable energy production. So, it’s not surprising that several studies are exploring the possibility.

In September, the researchers at Rice University devised a way to convert the CO2 to pure liquid fuel using an electrolyzer. Now a study from the Argonne National Laboratory has managed a similar feat.

Instead of an electrolyzer, the researchers used sunlight and a catalyst that’s primarily made of copper to transform CO2 into methanol.

Speaking about the project, Argonne distinguished fellow and author of the study, Tijana Rajh said:

“We had this idea of copying photosynthesis, which uses carbon dioxide to make food, so why couldn’t we use it to make fuel.”

Rajh and colleagues soon discovered how complex the problem was. To make methanol from carbon dioxide, you need not just one electron, but six.

They figured out a way to do just that.

Using a Photocatalyst to Convert Carbon dioxide to Liquid Methanol

Past attempts at using a photocatalyst to convert CO2 into fuel involved using titanium dioxide. Unfortunately, this resulted in a blend of various products, including aldehydes and methane.

Since the reactions lacked selectivity, it was almost impossible to isolate a usable fuel stream, says the Rajh.

In the new study, the researchers replaced titanium oxide with cuprous oxide. It has a more negative conduction band and is more selective in terms of product.

This resulted in a catalyst with a sort of a split personality.

The resulting cuprous oxide microparticle had various facets, many of which are inert. However, one of the facets is very active in driving the reduction of carbon dioxide to methanol.

“Carbon dioxide is such a stable molecule, and it results from the burning of basically everything,” Rajh said. “So the question is, how do we fight nature and go from a really stable end product to something useful and energy-rich.”

Although the study figured out a way to convert carbon dioxide into useful energy, it may not be enough to curb emissions.

Despite current efforts to reduce emissions, CO2 concentration in the atmosphere hit an all-time high last year. And it’s on track to hit another record high in 2019.