Catalyst helps convert waste CO2 into fuel

There's a basic contradiction between modern lifestyles and environmental protection: The more we consume, the more we produce and the more damage we cause to the environment.

But what if carbon dioxide emissions could be recycled?

Since the 1990s, scientists have been working on making liquid fuel from carbon emissions. However, one of the major bottlenecks is finding the proper catalysts and how to use them.

On Thursday, scientists from the University of Science and Technology of China reported a new catalytic mechanism to create liquid fuel from carbon dioxide. The study was published by the British scientific journal Nature.

"Driven by increasing concerns about CO2-induced global warming and depletion of finite fossil fuel resources, developing renewable energy alternatives represents one of the major scientific challenges of the 21st century", said Xie Yi, a professor at the university and a member of the Chinese Academy of Sciences.

"In this regard, electrochemical reduction of waste CO2 into useful energy-rich fuels is considered a potentially clean strategy for turning trash into treasure," she said.

Xie's team used cobalt, an element that usually exists in nature in chemically combined form, as a catalyst to convert carbon dioxide into formate, which can be used as liquid fuel.

"Cobalt has been considered nearly non-catalytic for this reaction before, but we have demonstrated it as a very active catalyst if placed in the correct condition," said Gao Shan, one of the nine authors of the paper.

Carbon dioxide reduction - the chemical process to convert CO2 into multiple chemical products, including those that can be used as liquid fuel - has required too much energy to be feasible.

The Chinese scientists evaluated the activity of cobalt in two different forms: pure cobalt metal and co-existing domains of cobalt metal and cobalt oxide.

"Carbon dioxide reduction to formate has never before been reported for cobalt, despite the long history of the field and numerous surveys of metallic electrodes by multiple authors," said an anonymous peer review comment provided by Nature.

The new catalysis results may cause many to rethink the accepted strategies for the reaction, according to the review.

Industrial applications of the technology still face a number of challenges besides the chemical reaction itself, such as collecting CO2 and gathering the produced fuel, according to Gao.

"There are several teams around the globe devoted to related research. It is hard to tell who is doing better, since each team has its own emphasis and so many trivial things need to be explored," he said.