(666g) Sonocatalytic Formation of Syngas from Carbon Dioxide and Water Using Cu-Based Catalysts

Sonochemistry employs high frequency sound waves to generate cavitation bubbles to facilitate or enable unique chemistries under bulk ambient conditions. These cavitation bubbles may undergo a pseudo-adiabatic collapse leading to internal bubble temperatures that exceed 5000°C. This high-energy microenvironment can break most molecular bonds under ambient bulk temperatures. Such conditions may be beneficial for breaking the C-O bonds in carbon dioxide and the H-O bonds in water to form a mix of radical species that may produce syngas. Furthermore, sonochemistry can be powered by sources of renewable energy and is considered a ‘green’ chemical process.

We have recently devised a novel sonochemical reactor that utilizes cylindrically converging acoustic waves to amplify acoustic pressures and concentrate cavitation. The work presented here demonstrates the potential of using sonochemistry in combination with catalysts to convert CO2 to syngas directly from CO2-saturated water. In this work, hydrogen and carbon monoxide were measured using gas chromatography.

Specifically, we explored the yield and rate of syngas production from various Cu-based catalysts in our sonochemical reactor. We also observed the impact of sonochemistry on the structures of the catalyst after each reaction. Additionally, the production of syngas was shown to be greatly impacted by not only the catalyst, but also the acoustic and solvent conditions. Understanding the optimal path towards sonochemical syngas production may also provide insights into the reduction of CO2 into hydrocarbons, creating a one-pot sonochemical Fischer-Tropsch process.