The equilibrium species and theoretical electromotive force of cells fed with NH3 and 3% H2O humidified H2

CH4

C3H8 and underground coal gasification(UCG)gas on the basis of minimum Gibbs free energy were calculated

whilst the open circuit voltage(OCV)

V-I characteristics and long-term stability of NiO-GDC‖GDC‖Ba0.9Co0.7Fe0.2Nb0.1O3-δ(B0.9CFN)anode-supported cells operated in above five fuels were evaluated.The results showed that direct utilization of hydrocarbon fuels in anode could achieve a desirable electromotive force (EMF)no less than 1.05 V

while the OCV for ceria-based cells was comparatively poorer due to the presence of electronic conductivity.Besides

the synergy effect between stagnant kinetics of hydrocarbons reforming and the relatively sufficient O2- supply due to fast migration of oxide ions suppressed carbon deposition at low operating temperatures for ceria-based SOFC. Furthermore

the UCG gas fed cell exhibited peak power densities as high as 0.151

0.299

0.537 and 0.729 W·cm-2

respectively at 500

550

600 and 650℃

and showed no evident performance decay and carbon deposition on anode after discharging at 600℃ under a constant voltage of 0.6 V for 120 h

thereby demonstrating UCG gas is a promising fuel for direct utilization in SOFC.