Catalysts for Clean Energy: A Review on Current Progress for the Catalyzed Recycling of CO₂ into Dimethyl Ether

Dimethyl ether (DME), one of the proposed targets for CO₂ recycling, is a very attractive renewable energy source due to its non-toxic nature, low environmental impact, and hydrogen (H₂)-carrying abilities. The thermal catalyzed reaction of CO₂ to DME requires two steps with different catalysts, and the combination and optimization of these catalysts are of great importance for achieving viable DME yield that would make future industrial implementation possible. The thermodynamics and reaction mechanisms of the CO₂ conversion to DME were discussed. The metallic and acidic catalyst functions utilized for this reaction are analyzed in this review, and the different methods of combination are presented with a focus on hybrid catalysts to achieve successful and efficient catalyzed reactions with optimized DME yield. Additionally, an outlook for future directions in catalyst development and mechanistic understanding in this largely overlooked area are provided.