Conversion of methane into value-added products in catalytic-assisted solid oxide fuel cell

Abstract

Separating catalytic and electrochemical reactions at the fuel electrode of the direct methane solid oxide fuel cell (SOFC) produces syngas and C2 products (ethane and ethylene), while cogenerating electricity. A SOFC-compatible La0.5Ce0.5O2-δ catalyst is first validated for the oxidative coupling of methane (OCM) reactions with O2 and H2O oxidizing agents in a fixed-bed reactor. It is then applied as a catalytic layer on the current collector of a standard nickel/yttria-stabilized zirconia (Ni/YSZ) anode. A systematic study of operating parameters such as temperature, fuel concentration, flow rate, and applied current reveals a maximum C2 production rate of 1.5 mmol min−1 cm−2 and over 50 % selectivity for syngas (H2/CO ∼ 1). Experimental results, supported by thermodynamic data, indicate that steam generated by electrochemical hydrogen oxidation promotes both steam reforming and methane oxidative coupling within the catalytic layer, ensuring stable SOFC operation. This innovative fuel electrode configuration, featuring an OCM-active layer, enables efficient catalytic-assisted conversion of methane into value-added products within a SOFC.