Reaction mechanisms of carbon dioxide methanation

Constant increase of carbon dioxide emissions from anthropogenic activities leads to the search of options for its recycling and utilization. Although recycled CO₂ utilization as a raw material for the production of chemicals and propellants can be challenging, it is the most sustainable way to mitigate its emissions. Among the most promising applications of CO₂ is its catalytic fixation with hydrogen via the methanation reaction to methane. CO₂ methanation, depending on the used catalyst and overall reaction conditions, can proceed through different mechanism or pathways. A literature review on the methanation reaction mechanism shows that CO₂ can be converted to methane either by direct methanation or through the formation of a CO intermediate. This article analyses the proposed reaction mechanisms of CO₂ methanation.