Robust nickel silicate catalysts with high Ni loading for CO₂ methanation.

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Carbon dioxide (CO2) is a major greenhouse gas and a potential carbon source.
• CO2 methanation produces methane, a valuable fuel, but faces challenges with catalyst stability.
• Nickel-based catalysts are effective but prone to nanoparticle sintering during CO2 methanation.

Purpose of the Study:

• To synthesize efficient and robust nickel silicate catalysts (NiPS-X) for CO2 methanation.
• To investigate the effect of nickel loading on catalyst structure and performance.
• To overcome the sintering issue of nickel nanoparticles in CO2 methanation.

Main Methods:

• Hydrothermal synthesis of nickel silicate catalysts (NiPS-X) from nickel phyllosilicate.
• Systematic variation of nickel content in the NiPS-X catalysts.
• Evaluation of catalytic performance in CO2 methanation, including conversion and selectivity.

Main Results:

• Catalytic performance increased with higher nickel loading.
• The NiPS-1.6 catalyst, with 34.3 wt% Ni, showed >80% CO2 conversion and ~100% methane selectivity for 48 hours.
• High dispersion of Ni nanoparticles and strong metal-support interaction were observed.

Conclusions:

• Nickel loading is critical for the performance of NiPS-X catalysts.
• The unique layered silicate structure and Lewis acid sites contribute to the catalyst's excellent stability and activity.
• The developed NiPS-X catalysts offer a promising solution for CO2 utilization and sustainable fuel production.