Sustainable Liquid Fuel Production | Measuring Solid-Electrolyte Interphase

This seminar will highlight the work of two of the winners of the Stanford Energy Student Lecture series.

Carbonate-catalyzed CO2 hydrogenation for sustainable liquid fuel production

Despite increasing electrification, generating carbon-neutral liquid fuels remains critical for decarbonizing sectors that cannot readily electrify. Recently commercialized gas fermentation, a technology that makes alcohols from CO and H2, has created a new opportunity for sustainable liquid fuel production provided that CO and H2 can be sourced renewably. While H2 can be made from water electrolysis, the renewable production of CO remains a challenge. Here, we demonstrate a scalable, selective, and stable thermochemical catalyst that upgrades H2 and CO2 into a CO-containing feedstock appropriate for gas fermentation to ethanol. The combination of water electrolysis, our process, and gas fermentation could convert electricity into ethanol fuel with nearly 50% overall energy efficiency, highlighting a unique opportunity to generate renewable liquid fuels at scale.

Speaker: Chastity Li, Stanford University

Quantification of solid-electrolyte interphase composition during nonaqueous electrochemical nitrogen reduction

To accommodate the growing population and decarbonize synthetic ammonia (NH3) production, electrified alternatives to Haber-Bosch must be developed. However, electrified methods are often hindered by poor selectivity to NH3, which is underpinned by a poorly formed solid-electrolyte interphase (SEI) layer on the cathode surface. In this work, our novel quantitative SEI composition measurements reveal that SEI growth coincides with improved Faradaic efficiency to NH3, suggesting that the SEI acts as a membrane which selectively hinders transport of ethanol while still allowing N2 transport to the cathode surface. Our findings provide important insights for the rational design of electrolytes to impart beneficial SEI properties which can improve selectivity in emerging electrochemical NH3 synthesis systems.