Guiding CO2 Electrolyzer Material Designs Through Advanced Operando Characterization

为了减缓人为气候变化和解决全球能源不平等问题，需要清洁能源解决方案来防止二氧化碳在大气中的积累。二氧化碳电解具有将CO2转化为有用燃料的潜力，但其工业吸收受到多孔阴极气体扩散电极（GDE）的低效材料设计的阻碍。因此，碳酸盐积聚在GDE中，阻塞反应位点并导致感兴趣的产物气体（例如一氧化碳、氢气、甲烷和乙烷）的低选择性。为了应对这些挑战，Bazylak教授和她的团队建议采用动态操作同步辐射成像与化学表征相结合，以全面表征CO2电解槽中的传质限制。从这项工作中获得的见解将用于开发下一代CO2 GDE，用于高效电解槽操作。为了进行全面的性能表征，Bazylak教授建议使用多通道恒电位仪系统与在线气相色谱仪（GC）相结合。多通道恒电位仪将用于评估电化学性能，而在线GC将量化CO2还原反应的产物。这样，法拉第效率（促进CO2还原反应的电子效率）的动态变化可以与碳酸盐形成（通过操作成像）相关联。多通道恒电位仪还能够进行局部临界电流密度测量，以推断碳酸盐形成对CO2传输的直接影响。该设备将使研究有可能加速CO2电解槽的开发，优化生产有价值的化学品，以促进CO2还原反应的新能源储存途径的发展，并进一步提高加拿大在清洁能源研究方面的领导地位。

To mitigate anthropogenic climate change and address global energy inequality, clean energy solutions to prevent the accumulation of CO2 in the atmosphere are required. Carbon dioxide electrolysis has the potential to convert CO2 into useful fuels, but its industrial uptake is hindered by inefficient material design at the porous cathode gas diffusion electrode (GDE). As such, carbonate salts accumulate in the GDE, blocking reaction sites and resulting in low selectivity of product gases of interest, such as carbon monoxide, hydrogen, methane, and ethane. To address these challenges, Prof. Bazylak and her team propose to employ dynamic operando synchrotron imaging coupled with chemical characterization to comprehensively characterize mass transport limitations in CO2 electrolyzers. The insights gained from this work will be used to develop the next generation of CO2 GDEs for high efficiency electrolyzer operation. For comprehensive performance characterization, Prof. Bazylak proposes the use of a multichannel potentiostat system coupled with an online gas chromatograph (GC). The multichannel potentiostat will be used to assess electrochemical performance, while the online GC will quantify the products of the CO2 reduction reaction. This way, dynamic changes in faradaic efficiency (efficiency of electrons facilitating the CO2 reduction reaction) can be correlated to carbonate salt formation (through operando imaging). The multichannel potentiostat further enables localized critical current density measurements to deduce the direct effects of carbonate salt formation on CO2 transport. This equipment will enable research that has the potential to accelerate the development of CO2 electrolyzers optimized for the production of valuable chemicals needed for the advancement of new energy storage pathways from CO2 reduction reactions, and further Canada's leadership in clean energy research.