(277a) Durability of Anion Exchange Membrane CO2 Electrolyzer When Exposed to Flue Gas

Carbon dioxide (CO₂) is the largest contributor among the global warming gases and is responsible for increasing temperatures through a process called the greenhouse effect. One way to mitigate CO₂ is to convert CO₂ electrochemically into value-added chemicals such as C1 (carbon monoxide, formate/formic acid) and C₂+ products. Amongst these technologies, electrochemical reduction of CO₂ to CO is most mature technology in laboratory. Stable performance of CO₂ electrolysis to CO and O₂ for up to 4000hrs with negligible degradation has been demonstrated when operating with pure CO₂ ^1,2. However, industrial CO₂ sources usually contain other species such as nitrogen (N₂), Oxygen (O₂), nitrogen oxides (NO_x), volatile sulfur compounds (VSC: SO₂, H₂S, COS), volatile oxygenates (VO_X: ethanol) and volatile hydrocarbons (VHC). In this work, we investigate the effects of H₂S up to 25ppm in CO₂ on the performance of anion exchange membrane CO₂ electrolyzers (AEMCEs). Figure 1 shows the stable performance of AEMCE for up to 3000hr. We will discuss the possible degradation mechanisms related to H₂S.

Figure 1 Long term stability of CO₂ electrolyzer running at 500mA (100mA/cm²) in the presence of 3ppm of H₂S in CO₂ stream