Tuning Ce-doping La0.7Sr0.3Fe0.9Ni0.1O3-δ internal reforming catalyst to enhanced conversion efficiency and coking tolerance of solid oxide fuel cells fueled by oxygen-bearing low concentration coal mine methane

Abstract

Solid oxide fuel cells (SOFCs) possess the potential to directly utilize abundant low concentration coal mine methane for power generation, which is crucial for energy conservation and reducing greenhouse gas emissions. Herein, Ce-doped La0.55Ce0.15Sr0.3Fe0.9Ni0.1O3-δ (LCSFN) perovskite is firstly employed as an anode internal reforming catalyst to enhance the electrochemical performance, stability, and resistance against carbon deposition in SOFCs. The results demonstrate that Ni-Fe alloy nanoparticles can be effectively precipitated from LCSFN under reducing atmosphere, thereby significantly promoting the partial oxidation reaction of methane while preventing direct contact between methane and Ni particles for the anode. The anode-supported single cells demonstrated exceptional electrochemical performance using a composite catalytic layer consisting of LCSFN-Ce0.9Gd0.1O2-δ (LCSFN-GDC). At 800℃, the utilization of both H2 and 16 %CH4-1 %O2-N2 resulted in the attainment of maximum power densities (MPD) measuring 881.66 mW·cm−2 and 824.69 mW·cm−2, respectively, with the recorded values for polarization resistance were 0.32 and 1.16 Ω·cm2. Additionally, the single cells equipped with LCSFN-GDC internal reforming catalytic exhibit remarkable resistance to carbon deposition, maintaining stable performance for a duration of 100 h using 16 %CH4-1 %O2-N2. These findings underscore the efficacy of methane catalysts in SOFCs, as it not only enhances power generation efficiency through using internal reforming catalyst but also ensures long-term stability by mitigating carbon-related issues.