Catalysis effect on CO₂ methanation using MgH₂ as a portable hydrogen medium

Area of Science:

• Materials Science
• Chemical Engineering
• Catalysis

Background:

• Carbon dioxide (CO2) utilization is crucial for mitigating climate change.
• Magnesium hydride (MgH2) is a potential solid-state hydrogen source.
• Thermochemical reduction of CO2 to methane (CH4) offers a sustainable energy pathway.

Purpose of the Study:

• Investigate the feasibility of CO2 reduction to CH4 using MgH2.
• Evaluate the catalytic effect of cobalt (Co) on the reaction.
• Optimize reaction conditions for efficient methane production.

Main Methods:

• Experimental investigation of CO2 reduction with MgH2 under varying conditions (temperature, time, molar ratio).
• Comparative study of catalyzed (Co) and uncatalyzed reactions.
• Analysis of reaction mechanisms, including Sabatier and reverse water-gas shift reactions.

Main Results:

• Uncatalyzed reaction yielded 44.6% CH4 at 400 °C after 24 h.
• Cobalt-catalyzed reaction achieved 78% CH4 yield at 350 °C after 48 h with a 4:1 MgH2:CO2 ratio.
• Catalysis lowered operational temperature without compromising methane yield.

Conclusions:

• Cobalt significantly enhances the thermochemical reduction of CO2 to CH4 using MgH2.
• Optimized conditions demonstrate a viable method for CO2 conversion to a valuable fuel.
• This research provides insights into using solid hydrogen storage materials for CO2 valorization.