Adsorption thermodynamics of methane reforming over solid oxide fuel cell anodes

Abstract

Adsorption kinetics and thermodynamics on nickel base anode materials remain underexplored under reforming conditions when fuelled directly with methane. The kinetics determine how quickly and effectively reactant gases interact on the anode surfaces, affecting the behavior of subsequent electrochemical reactions. However, the complexity of these interactions under operating conditions have led to a limited number of detailed studies in this area. Thus, further investigation into adsorption kinetics could unlock new possibilities for optimizing fuel cell performance. This study examines the adsorption Gibbs free energy of reactants on the anode in solid oxide fuel cell to assess the electrocatalyst activity. Our findings reveal that H₂O exhibits more favorable adsorption conditions than CO₂ on the catalyst surface, and increased temperature and current density lead to different surface adsorption behaviours. The results show that steam reforming prevents coke formation on the fuel cell anode more effectively than dry reforming. This proposed method can also be used to examine the coke resistance and the performance of anode structures during the investigation and development stages for fuel cell research. The study provides valuable insights into anode performance and offers a foundation for future advancements in SOFC technology.