NiO Nano- and Microparticles Prepared by Solvothermal Method-Amazing Catalysts for CO₂ Methanation

Area of Science:

• Materials Science
• Catalysis
• Chemical Engineering

Background:

• Nickel oxide (NiO) is a key catalyst in heterogeneous catalysis, particularly for CO2 hydrogenation and methanation in Fischer-Tropsch reactions.
• The efficiency of NiO catalysts is significantly influenced by the morphology, size, and surface area of its microparticles (MPs) and nanoparticles (NPs).

Purpose of the Study:

• To synthesize NiO micro- and nanoparticles with controlled morphologies using a solvothermal method.
• To evaluate the performance of different NiO morphologies in CO2 hydrogenation for methane production.

Main Methods:

• Solvothermal synthesis was employed to prepare various NiO morphologies, including microspheres, sheet clusters, hexagonal microparticles, and nanodiscs.
• Gas-phase hydrogenation of CO2 was performed using the synthesized NiO catalysts.
• Catalyst performance was assessed based on CO2 conversion and CH4 selectivity.

Main Results:

• The solvothermal method successfully produced NiO MPs and NPs with diverse morphologies.
• NiO catalysts demonstrated excellent conversion rates and high selectivity for CH4 production.
• NiO with disc or sphere morphology exhibited optimal performance, achieving near 100% CH4 selectivity and approximately 90% CO2 conversion.

Conclusions:

• The morphology of NiO significantly impacts its catalytic activity in CO2 hydrogenation.
• NiO microspheres and nanodiscs are highly effective catalysts for producing methane from CO2.
• The solvothermal synthesis offers a viable route for developing high-performance NiO hydrogenation catalysts.