Development of carbon resistant Solid Oxide Electrolyzer Cells (SOEC) for CO2 utilization

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High levels of atmospheric CO2 are causing climate change, which creates more extreme weather patterns, among other problems. The transition to energy systems with no or low CO2 emissions must be expedited, but it will take time. As we move towards a renewable energy-based future, we must cope with the CO2 produced by our current fossil fuel-based energy paradigm. Proposed workarounds include carbon capture and storage (CCS) and carbon capture and utilization (CCU). In CCS, CO2 is captured and injected into geological formations. While CCS can sequester large amounts of CO2, it can be done only in limited locations. In CCU, captured CO2 is used to produce chemicals and fuels. Although CO2 can be used directly as feedstock, it is advantageous to first convert CO2 to carbon monoxide (CO) and then use the CO, usually with hydrogen (H2), to form new products. CO2 can be converted to CO through electrolysis, where electricity breaks CO2 in CO. Solid oxide electrolysis cells (SOECs) use electricity to convert CO2 and H2O into CO and H2. Provinces, like Ontario where electricity is generated with low CO2 emissions, are well-positioned to capitalize on this technology. Furthermore, SOECs can be well-suited for electricity that originates from renewable energy, which is characterized by intermittent operation. In the proposed work, we will consider how to advance the development of SOEC for CO2 utilization by developing a new effective, stable and thermal cycling tolerant SOEC. Conventional SOECs are made of ceramic materials. Nickel, which has excellent activity, is commonly used as a cathode electrocatalyst; however, CO2 makes it prone to carbon deposition which hinders the cell's performance. Promising alternatives, such as perovskites, do not have this problem, but their activity is still too low to be effective. Metal-supported SOECs (MS-SOEC), which incorporate thin electrodes and electrolyte layers deposited on a metal support, provide a good alternative to the all-ceramic cell. Their high tolerance to thermal and redox cycling makes them ideally suited for intermittent renewable energy sources, but they are prone to carbon deposition due to the Ni used. The proposed work aims to combine the benefits of perovskite's coking resistance and the metal-supported cell's better cycling tolerance through the development of a MS-SOEC with a perovskite-based cathode that will achieve high stability and activity toward CO2 electrolysis. To achieve this objective, we will 1) change the perovskite's composition and structure to develop more active and stable materials at the cathode; 2) deposit electrospun nanofibers to develop a more active anode; 3) devise a procedure to infiltrate the new cathode perovskite material at the MS-SOEC cathode; and 4) combine all steps to fabricate a complete cell. This will involve a combination of experiments, theoretical studies, and advanced simulation to accurately predict carbon deposition.