Dry Reforming of Methane on Ni/Nanorod-CeO2 Catalysts Prepared by One-Pot Hydrothermal Synthesis: The Effect of Ni Content on Structure, Activity, and Stability

The nanorod morphology of the CeO2 support has been recognized as more beneficial than other morphologies for catalytic activity in dry reforming methane. Ni/nanorod-CeO2 catalysts with different Ni contents were prepared by one-pot hydrothermal synthesis. Samples characterized X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR), desorption (H2-TPD), field emission scanning electron microscopy/energy dispersive spectroscopy (FE-SEM/EDS), Brunauer–Emmet–Teller (BET) and Barrett–Joyner–Halenda (BHJ) analysis. effect content on size intrinsic strain ceria was analyzed Size–Strain plot Williamson–Hall XRD data. average particle dispersion determined H2-TPD. H2-TPR analysis revealed a strong Ni–support interaction that limited nickel sintering. methane tested stoichiometric mixture CO2:CH4:N2:He = 20:20:20:140, gas hourly space velocity (GHSV) 300 L g−1 h−1, temperatures range 545–800 °C. turnover frequency (TOF) value increased linearly 5.5–33 nm, suggesting structure sensitivity reaction. loading 4–12 wt.% showed high H2/CO selectivity stability over time stream, whereas sample 2 less selective underwent rapid deactivation. Only small amount nanotubular carbon observed FE-SEM after time-on-stream experiment. Deactivation low-Ni-content is ascribed to easier oxidation particles.