Exceptional Durability of Solid Oxide Cells

Extensive efforts to resolve the degradation normally associated with solid oxide electrolysis cells SOECs have been conducted during the past decade. To date, the degradation is assumed to be caused by adsorption of impurities in the cathode, although no firm evidence for this degradation mechanism has been presented. In this article, we demonstrate that the rapid degradation of these SOECs is indeed caused by impurities, and that operation without degradation is possible when removing these impurities from the inlet gases. Cleaning the inlet gases may be a solution for operating SOECs without long-term degradation. Production of synthetic hydrocarbon fuels from renewable energy is a solution to reduce oil consumption and carbon dioxide emissions without the need for modifications of existing infrastructure, e.g., in the production of methane synthetic natural gas or petrol/diesel, the infrastructure already exists in many countries. The raw material for synthetic hydrocarbon fuels is synthesis gas H2 +C O, which is traditionally produced via coal gasification or steam reforming of natural gas. Both processes consume fossil fuels and emit greenhouse gases. Coelectrolysis of H2O and CO2 H2O +C O2 → H2 cathode +C Ocathode +O 2 anode using renewable energy sources may be an alternative route for producing synthesis gas without consumption of fossil fuels and without emitting greenhouse gases. CO2 captured from air and/or recycling or reusing of CO2 from energy systems combined with coelectrolysis of H2O and CO2 seems to be an attractive method to provide CO2 neutral synthetic hydrocarbon fuels. Solid oxide electrolysis cells SOECs have the potential for cost-competitive production of hydrogen 1-4 and carbon monoxide, 1