Synthesis and characterisation of La-Co/MgO catalyst for methane dry reforming

In the present work, different loadings of lanthanum cobalt supported on magnesia catalysts were prepared for the methane dry reforming. The BET specific surface area has declined with the increment of La loading although pore volume increased significantly beyond 1 wt% La doping. The 5 wt% La-Co/MgO catalyst has BET specific surface area of 31.67 m²/g and 0.30 cm³/g of pore volume. From FESEM imaging, an addition of lanthanum promoter has created solid with smaller particle size. This is consistent with XRD analysis where crystallite size significantly dropped when the percentage of La was higher. XRD showed that the peaks representing CO₃O₄ occurred at 2θ = 37.0° and MgO or Co/MgO at 2θ = 42.9°, 62.3°, 74.7° and 78.6°. As lanthanum loading increased, the crystallite size dropped from 24.5 to 17.9 nm at peak 2θ = 42.9° while the crystallite size decreased from 23.5 to 17.1 nm at peak 2θ = 62.3°. Reaction studies have found that 5wt% La catalyst gave the highest rate formation of product yield (H₂ and CO). However, the composition of product yields was quite low at about 1.6% (differential reactor). It was also found that the rate was optimum at CO₂:CH₄ feed ratio of 0.67.