Enhancement of methanation of bio-syngas over CeO2-modified Ni/Al2O3 catalysts

CeO2 modified Ni/Al2O3 catalysts were developed for synthetic natural gas (SNG) from bio-syngas methanation. Physiochemical properties of the CeO2 modified Ni/Al2O3 catalysts were characterized by N2 physical adsorption (BET), scanning electron microscopy (SEM), temperature-programmed reduction of hydrogen (H2-TPR), X-ray diffraction (XRD) and thermo gravimetric analyzer (TGA). The bio-syngas methanation tests showed that adding 60 wt.% of CeO2 in the Ni/CeO2-Al2O3 catalyst presented excellent bio-syngas methanation performances (91.6% carbon oxides conversion with 92% CH4 selectivity) at low temperature (350 °C). The characterization results indicated that adding of CeO2 into Ni/Al2O3 strengthened the NiO-CeO2 interaction via the weakening of the interaction between Ni species and Al2O3, facilitating the separation of NiO from NiAl2O4. The optimal CeO2 content of 60 wt.% was obtained to disperse well Ni species and increase active metallic Ni sites, promoting the catalytic performances for bio-syngas methanation to SNG.