(562c) An Integrated CO2 Capture and Conversion Device based on Metal-Organic Framework -and Cu Nanostructured Electrocatalyst

There is no doubt that CO₂ emissions and its proportion in the atmosphere are rising sharply due to growing world population and as a result of fossil fuel production and consumption outcomes. This is a significant motivation for the scientific community to focus on CO₂ capture and utilization strategies to make carbon-based chemical feedstocks. One such process, the electrochemical CO₂ reduction reaction, enables the conversion of CO₂ into valuable hydrocarbons and alcohols. However, efficient electrocatalysts need to be employed for CO₂ reduction reaction to become competitive with traditional fossil fuel‐based technologies.

On the other hand, emerging research into organic and inorganic hybrids and Metal-Organic-Frameworks “MOF” have shown promise as a new class of porous materials with micropores or mesopores. Because recent MOF research has shown high capacity and selectivity towards CO₂ capture even at ambient temperature, it appears promising as a possible material to serve as a catalyst or concentrator for CO₂ conversion. In this study, we are developing an integrated device, wherein MOF based porous materials serve as CO₂ concentrator and subsequently a Cu based nanostructured catalyst electrochemically converts CO₂ into valuable C₂+ based products. Carbon fiber sheet was used as a platform to conduct the current and support the MOF and Cu catalyst for CO₂ capture and electrochemical reduction reaction, respectively. One side of the carbon fiber is coated with Zinc-based MOF with 500 m²/g Langmuir surface area, and an adsorption capacity of 4 mmol/g CO₂ at 20℃. The MOF particles were synthesized in-house and followed with a set of characterizations including, TGA, XRD, FTIR, and gas sorption. The MOF layer served as a CO₂ concentrator and a screening stage, where it allows higher percentage of CO₂ molecules to pass through the fiber to the other side. The other side of the fiber was coated with Cu₂O particles to catalyze the electrochemical reduction reaction. Spray coating technique was used to spray coat MOF and Cu₂O onto the carbon fiber. The spray coating process took place after individually mixing the Cu₂O and MOF particles in Methanol/Nafion solution to maintain a certain level of rigidness and stability on the substrate surface. Binary gas feed N₂ 50%/CO₂ 50% was used for the electrochemical reduction experiments in a flow-cell configuration. The initial results showed high C₂+ products selectivity, conversion efficiency, and catalyst stability.