CO-promoted low-temperature conversion of CH4 to hydrogen and carbon nanotubes on Nanocrystalline Cr-doped ferrite catalyst

Catalytic decomposition of methane (CDM) to H2 and multiwalled carbon nanotubes (MWCNTs) was achieved by a nanocrystalline Cr-doped ferrite (FeCr) catalyst at 500 °C and atmospheric pressure with minor cofed CO. The exothermic Boudouard reaction increased the temperature and H2 from CDM at catalyst surface that induced Fe2+ reduction to Fe0. The Fe0 clusters along with the CO-originated surface oxygens enabled transfer of C and H to sustain the surface CDM and CO reactions. The metallic Fe-enabled C transfer led to the formation of MWCNTs. The Cr6+/3+ dopants facilitated the Fe redox cycles and maintained surface oxygens for high catalytic activity.