Efficient conversion of low-concentration coal mine methane by solid oxide fuel cell with in-situ formed nanocomposite catalyst

Solid oxide fuel cell is promising to efficiently convert the low-concentration coal mine methane (methane concentration c(CH4) < 30%) from pollutant to clean energy. However, the low internal reforming performance and the coking at anode become the big challenges of SOFC using LC-CMM. Therefore, the Mo-doped NiTiO3 catalyst layer is fabricated over SOFC anode in this work. The catalyst can be in-situ reduced to nanoscale Ni and Mo-doped TiO2-delta composite catalyst with plentiful oxygen vacancies, thus adsorbing oxygen species to enhance CH4 internal reforming and remove carbon. It is demonstrated that the catalyst-modified SOFC using LC-CMM exhibits the much better electrochemical performance, anti-carbon effect and discharging stability than the un-modified SOFC. The modified SOFC also shows the good electrochemical and internal reforming performances under different LC-CMM with various methane concentration c(CH4) and oxygen concentration c(O-2). The distribution of relaxation time (DRT) indicates that the catalyst can remove carbon and facilitates the adsorption, dissociation and transport of surface species through the enhanced oxygen-species mediated surface reactions. Besides, a 2D multi-physics coupling model is built to study the reforming-enhancing and anti-carbon mechanisms of the catalyst layer.

Automated summary

The Mo-doped NiTiO3 catalyst layer in solid oxide fuel cell can efficiently convert low-concentration coal mine methane to clean energy, while improving electrochemical performance and carbon resistance.