Turning CO2 into Fuel
by Andrew Myers (American Energy Society) … Recycling CO2 emissions themselves as researchers at Stanford University are doing has shown some promising results. They are turning carbon dioxide from car exhaust pipes and other sources into fuels like natural gas and propane.
Several recent studies have shown some success in this conversion. For instance, an engineering research group at Stanford University has found a process that yields four times more ethane, propane and butane than existing methods. While not a climate cure-all, the advance could significantly reduce the near-term impact on global warming. “One can imagine a carbon-neutral cycle that produces fuel from carbon dioxide and then burns it, creating new carbon dioxide that then gets turned back into fuel,” said Matteo Cargnello, an assistant professor of chemical engineering at Stanford who led the research.
Although the process is still just a lab-based prototype, the researchers expect it could be expanded enough to produce useable amounts of fuel. Much work remains, however, before the average consumer will be able to purchase products based on such technologies. Next steps include trying to reduce harmful byproducts from these reactions, such as the toxic pollutant carbon monoxide. The group is also developing ways to make other beneficial products, not just fuels. One such product is olefins, which can be used in a number of industrial applications and are the main ingredients for plastics.
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Cargnello thought completing both steps in a single reaction would be much more efficient and set about creating a new catalyst that could simultaneously strip an oxygen molecule off of CO2 and combine it with hydrogen. (Catalysts induce chemical reactions without being used up in the reaction themselves.) The team succeeded by combining ruthenium and iron oxide nanoparticles into a catalyst. “This nugget of ruthenium sits at the core and is encapsulated in an outer sheath of iron,” said Aisulu Aitbekova, a doctoral candidate in Cargnello’s lab and lead author of the paper. “This structure activates hydrocarbon formation from CO2. It improves the process start to finish.”
The team did not set out to create this core-shell structure but discovered it through collaboration with Simon Bare, distinguished staff scientist, and others at the SLAC National Accelerator Laboratory. SLAC’s sophisticated X-ray characterization technologies helped the researchers visualize and examine the structure of their new catalyst. Without this collaboration, Cargnello said they would not have discovered the optimal structure. “That’s when we began to engineer this material directly in a core-shell configuration. Then we showed that once we do that, hydrocarbon yields improve tremendously,” Cargnello said. “It is something about the structure specifically that helps the reactions along.”
Cargnello thinks the two catalysts act in tag-team fashion to improve the synthesis. READ MORE
Stanford researchers create new catalyst that can turn carbon dioxide into fuels (Stanford University)
