Factors That Limit the Performance of CO2 Electrolyzers

Wednesday, 4 October 2017: 15:40
National Harbor 8 (Gaylord National Resort and Convention Center)
H. Yang, Z. Liu, S. D. Sajjad, Y. Gao, J. J. Kaczur, and R. Masel (Dioxide Materials)
Carbon dioxide (CO2) electrolysis provides a pathway to turn waste CO2 into valuable fuels and chemicals but most previous efforts demonstrate low selectivity, high overpotential and low rates for the targeted products. In recent work Dioxide Materials has been using Sustainion™ imidazolium functionalized membranes and ionomers to improve the performance. Runs at a fixed current density of 200 mA/cmshowed that one can maintain 98% selectivity for six months at about 3 V applied potential, with a voltage increase of only 5 µV/hour. Other runs showed stable performance at 400 and 600 mA/cm².

Present areas for improvement of the technology include a better understanding of the processes that are occurring on the cathode catalysts, improving response to process upsets, developing cell designs that can be scaled to the m2 size and alternates to iridium as an anode catalyst. Initial work on these issues will be discussed.