Carbon dioxide (CO₂) is the main greenhouse gas, the excessive burning of fossil fuels leads to the increasing of CO₂ concentration, resulting in global warming. On the other hand, CO₂ is regarded as an ideal C₁ source due to its nontoxicity, abundance and availability. Hence, the transformation of CO₂ into fine chemicals and hydrocarbon fuels in organic synthesis is becoming one of hot research fields. Among them, the transition-metal catalyzed CO₂ hydrogenation is an appealing and promising approach for CO₂ utilization with wide potential applications, thus leading to selective fromation of 2e, 4e, and 6e reductive products including formic acid, formamide, formate, formaldehyde, methanol and C₂₊ alcohols under mild reaction conditions. In this review, the recent advances on transition metal complexe-catalyzed CO₂ hydrogenation are in detail summarized on the basis of the molecular structures, activities of the homogeneous catalysts, and product selectivity controlling. This review also gives an overview on the in situ catalytic hydrogenation corresponding to the recently developed CCU (CO₂ capture and utilization) strategy. Furthermore, the challenges and perspectives in homogeneous catalytic hydrogenation field are also given in this article.

Key words: carbon dioxide, organometallic complexes, homogeneous catalysis, hydrogenation, sustainable chemistry