(63v) Biogas Reforming with Addition of Carbon Dioxide to Syngas over Ni-Based Bimodal Pore Catalyst

Methane dry reforming of (MDR) has been widely studied due to its important applications in producing of syngas (CO + H₂), removal of two greenhouse gases, and upgrading of biogas (mainly composed of CH₂ and CO₂) into value added chemicals. Compared to the noble metal catalysts, nickel-based catalysts are suitable for industrial scaled-up MDR due to their high activity and low cost. However, nickel-based catalysts have been encountering a significant challenge that is the active metal sintering and coke deposition, leading to the catalyst deactivation and then the poor stability. Nevertheless, it has been reported that the deactivation of nickel catalysts can be suppressed by adding promoters like strong Lewis bases with the enhancement of chemisorb CO₂, such as MgO and CaO, and like lanthanide elements with the capacity of oxygen storage and release, such as CeO₂ and La₂O₃. Al₂O₃ is a commonly applied catalyst carrier own to its good pore size dispersion, high specific surface area and high mechanic strength.

            Herein, we report that the bimodal NiCeMgAl catalysts with different NiO-loading were synthesized by the refluxed co-precipitation method and were evaluated for MDR performance by using real biogas from anaerobic digestion of food wastes. The sample containing 15wt% NiO-loading (Ni₁₅CeMgAl) was found to be active enough at 750 °C with a high CH₄ conversion of around 90%. Ni₁₅CeMgAl catalysts kept their bimodal porosity after reduction and MDR process. The evolution of the Ni₁₅CeMgAl catalyst before and after MDR process was investigated by SEM, TEM, XRD, and TGA techniques. The correlation between the structure evolution and catalytic performance change was also discussed.