(569fy) Combining CO2 Reforming and CH4 Pyrolysis: Multifunctional Liquid Catalysts with Integrated Carbon Separation

The conversion of methane (CH₄) and carbon dioxide (CO₂) to value-added fuels and chemicals is becoming increasingly important because of the legislative demand for greenhouse gas mitigation. Dry reforming of methane (DRM), CH₄ + CO₂ ↔ 2 H₂ + 2 CO, is a well-studied reaction to convert CH₄ and CO₂ into synthesis gas, consisting primarily of carbon monoxide (CO) and hydrogen (H₂). By coupling with the methane pyrolysis reaction, CH₄ ↔ 2 H₂ + C, a 2:1 H₂ to CO ratio is produced, which is the stoichiometric ratio required for the Fischer Tropsch synthesis and methanol production.

Molten metals and alloys are effective in preventing coking and sintering during syngas production in bubble column reactors, which operate at high temperatures for simultaneous dry reforming and methane pyrolysis. My study will focus on these molten systems, where the low-density solid carbon produced floats on the melt surface for easy removal, ensuring it doesn't interfere with the reaction zone within the bubbles. This results in a continuously renewed catalyst at the bubble surface.

My research advances the study of the Ni-In catalyst's chemical looping mechanism, proposing indium oxide as an intermediate. I aim to develop new, more efficient, and cost-effective catalysts based on this mechanism. In my study, 23 liquid metals and alloys were evaluated, with Sn-In showing the highest performance, particularly at a 20:80 mol% Sn-In ratio, which demonstrated over 20 hours of stability in a bubble column reactor. A pulsed reaction experiment was conducted to explore the reaction mechanism, suggesting a new mechanism that may surpass the original chemical looping concept. Additionally, carbon residues collected from the melt's surface were analyzed using SEM to assess their structure and purity.