Effect of surface properties and NiO-MgO solid solution formation on CO₂ methanation over Ni/(Al₂O₃)_1-x(MgO)_x

Area of Science:

• Catalysis and Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Carbon dioxide (CO2) utilization is crucial for mitigating climate change.
• Methanation offers a pathway to convert CO2 into valuable methane (CH4).
• Nickel-based catalysts are promising for CO2 methanation due to their activity and cost-effectiveness.

Purpose of the Study:

• To develop and evaluate nickel catalysts for CO2 methanation.
• To investigate the influence of different supports (Al2O3, MgO, and MgO-Al2O3) on catalyst performance.
• To understand the relationship between catalyst surface properties, NiO-MgO solid solution formation, and catalytic activity.

Main Methods:

• Wet impregnation of 10 wt% nickel onto Al2O3, MgO, and MgO-Al2O3 supports.
• Catalytic activity testing for CO2 methanation.
• Characterization of catalyst properties (e.g., surface properties, NiO-support interaction, dispersion).

Main Results:

• The Ni/Al2O3 catalyst exhibited the highest methanation efficiency.
• Weak NiO-support interaction on Al2O3 facilitated easy reduction and higher nickel dispersion.
• The basicity of MgO and the formation of a NiO-MgO solid solution negatively impacted catalyst performance.

Conclusions:

• Alumina (Al2O3) is an effective support for nickel catalysts in CO2 methanation.
• Optimizing nickel-support interactions is key to enhancing catalyst efficiency.
• MgO-based supports and solid solution formation can hinder CO2 methanation performance.