The well-known Fischer-Tropsch process for the conversion of carbon monoxide and carbon dioxide has been explored by researchers around the world. However, the processes used to create the catalysts needed to convert carbon dioxide have been energy-intensive and therefore costly.

To date, methods have typically required the use of one catalyst to create the carbon support for the conversion process. Then the first catalyst has to be flushed out, and replaced with the second catalyst for the Fischer-Tropsch process. This is time and energy intensive, so makes the whole method expensive.

—Dr. Davide Mattia, project lead

With the new method, the same formed iron nanoparticles (NPs) used to catalyze the growth of the CNTs are activated in-line to act as catalysts for the CO and CO₂ reduction. This methodology negates the multiple steps associated with the purification and subsequent tethering of metal catalyst nanoparticles to CNT supports. The team’s results show superior CO and CO₂ conversion and selectivity to higher-order hydrocarbons when compared with a traditional system where iron NPs have been deposited onto CNTs from a solution.

Our method is considerably more simple. We use the same catalyst at both stages, which means energy and time isn’t required to purify the carbon support and the process can take place far more quickly. This makes our process scaleable to a level where it could be used in industry and have a significant impact on the environment.

—Dr. Matthew Jones, co-author

Looking to the future, the team hopes to explore the use of waste heat from power plants to run the process. Using waste heat would further reduce the energy required by our method, and in the future it could even become carbon neutral.

The research was funded by the Engineering and Physical Sciences Research Council (EPSRC), and the Centre for Sustainable Chemical Technologies and the Enterprise and Knowledge Exploitation team at the University.

Resources

• Justin P. O’Byrne, Rhodri E. Owen, Daniel R. Minett, Sofia I. Pascu, Pawel K. Plucinski, Matthew D. Jones and Davide Mattia (2013) High CO₂ and CO conversion to hydrocarbons using bridged Fe nanoparticles on carbon nanotubes. Catal. Sci. Technol. doi: 10.1039/C3CY20854K