The Effect of Anode Atmosphere on Hydrogen Production through Steam Electrolysis in a Solid Oxide Electrolysis Cell

High-temperature solid oxide electrolysis cells (SOECs) can achieve hydrogen production through water electrolysis at low voltage by introducing fuel gases to the anode side for oxidation reactions. However, research on the influence of different anode atmospheres and components on SOEC performance remains insufficient. In this study, a Ni-GDC/YSZ/Ni-YSZ electrolysis cell was employed to systematically compare the electrochemical behaviors under inert atmospheres and various reducing fuel atmospheres. The results show that reducing fuels significantly improves the electrolysis performance, with current densities of H 2 , CO, and CH 4 at 0.4 V reaching 0.73, 0.58, and 0.43 A / cm 2 , respectively. As for model biogas, as the CO 2 proportion increases ( CH 4 / CO 2 ratio from 1 ∶ 0 to 0.5 ∶ 0.5 ), the open-circuit voltage gradually approaches nearly 0 V, while the current density at 1.2 V remains within a decrease of 17.8% to 21.4% compared to that under pure methane atmosphere. This indicates that the Ni-GDC anode exhibits good tolerance and stability toward low-quality fuels containing CO 2 . This study provides a reference for the selection of anode fuels and research on the adaptability of SOECs to complex atmospheres.