PH3 Effects on the Electrochemical Degradation of SOFC Anode

Solid Oxide Fuel Cell anode is readily degraded by trace amount of Phosphine (PH₃) contaminant that is found in coal-derived syngas. PH₃ interacts with the anode material and affects its electrochemical performance by forming secondary phases. In this paper, the influence of the ppm level of PH₃ with moisture is investigated on the formation of secondary phases and hence on anode electrochemical performance degradation. Nickel yttria-stabilized zirconia (Ni-YSZ) anode shows immediate and severe electrochemical degradation due to PH₃ in moist hydrogen condition attributed to the nickel-phosphate secondary phase formation. Whereas in dry hydrogen condition, nickel-phosphide is preferred to form on the anode surface that shows less deleterious effects on SOFC performance as compared to nickel-phosphate.