Synthesis and Characterization of Ni-Cu/Al2O3-ZrO2 Nanocatalyst via Sequential Impregnation and Sol-Gel Methods Used in CH4/CO2 Conversion to Syngas

In this study, the effect of sol-gel method on the physicochemical properties of Ni-Cu/Al2O3-ZrO2 nanocatalyst was evaluated in comparison to sequential impregnation method. The nanocatalysts characterization was assessed by XRD, FESEM, PSD, EDS, FTIR, and TG-DTG analysis. The characterization results showed that a more uniform particle size distribution is obtained by the sol-gel method compared to the impregnation one. However, the surface area of this catalyst reduced due to the reduction of porous media and high particles density. Moreover, the sol-gel synthesis method led to the formation of very closely amorphous phases and the enhanced alkaline properties as a result of more –OH stretching vibration. Reforming of methane with CO2 was performed over Ni-Cu/Al2O3-ZrO2 at atmospheric pressure. The catalysts performance is inquired as a function of reaction temperature (550- 850 °C) and the results are reported in terms of feed conversion and syngas ratio. In the studied temperature range, it was found that the sol-gel synthesized catalyst showed a high activity. The best results were gained at 850 °C. Syngas ratio at this temperature was 0.94, which was very close to the stoichiometry ratio.