A survey of nickel-based catalysts and monolithic reformers of the onboard fuel reforming system for fuel cell APU applications

This paper presented a detailed survey of the catalysts for fuel reforming, including nickel-based catalysts with alkalis, alkaline earths, rare earths, noble metals, and hydrotalcite-type precursors. All these additions can enhance the Ni catalysts in regarding with activity, coke resistivity, and sintering resistivity. Smaller Ni particle size, more even particle dispersion, and less free NiO and NiAl₂O₄ can be obtained with these additions. Physicochemical characterization, activity, stability, coke resistance, and the effects of different precursors were summarized and compared. Development of the most commonly used monolithic reformer was also summarized, and different reformer configurations were presented chronologically. Homogeneous mixing of the completely evaporated fuel with air and steam, as well as uniform distribution of the mixture flow are the two main concerns in reformer design. Reforming energy conversion efficiency around 80%, power density above 3 kW/L, and specific power above 3 kW/kg are also reported in the most recent monolithic reformer.