Electrochemical and Operando Spectroscopic Studies of Sr₂Fe_1.5Mo_0.5O_{6‐<i>δ</i>} Anode Catalysts in Solid Oxide Fuel Cells Operating with Direct Alcohol Fuels

Abstract

Abstract A combination of operando Raman spectroscopy and chronoamperometry was used to examine the carbon tolerance of Sr 2 Fe 1.5 Mo 0.5 O 6‐δ (SFMO) electrode catalysts when operating with direct methanol and ethanol fuels in solid oxide fuel cells (SOFCs). Chronoamperometry studies revealed that these devices could maintain a steady power density output under typical SOFC operating conditions. High‐temperature Raman measurements of SFMO coupons exposed to methanol and ethanol (and their gas phase pyrolysis products) showed the presence of spectroscopic features associated with ordered and disordered forms of graphitic carbon. However, once SFMO was employed as an anode in an electrolyte‐supported SOFC, the graphite features disappear implying that these materials are not susceptible to carbon accumulation in functioning devices. These electrochemical and operando Raman measurements provided insight into SFMO's ability to act as an effective anode catalyst for SOFCs operating with direct alcohol fuel sources.