Recent Advancement of 3d Metal-Catalyzed Ethanol Upgradation via the Guerbet Reaction

The catalytic transformation of (bio)ethanol to butanol is a tempting method for improving the modest fuel qualities of this readily accessible bioderived feedstock into a molecule that possesses attributes substantially closer to standard gasoline. Through the use of borrowing hydrogen chemistry, longer-chain alcohols can be manufactured from their shorter-chain analogues via the Guerbet reaction, with the goal of using these long-chain alcohols as synthetic lubricants and sustainable fuels. Although this reaction for ethanol appears to be straightforward, it presents significant difficulties, particularly when trying to achieve high selectivity. Over the past century, there have been improvements in both heterogeneous and homogeneous catalysis by using noble metals, but there has been very little research conducted on 3d transition metal-based catalyst systems. This chapter emphasizes the findings of homogeneous and heterogeneous 3d metal-based catalyst systems that show promising results in terms of generating high activity and selectivity. While only Mn-based catalyst systems are known to catalyze this reaction under homogeneous conditions, metal oxide-supported systems dominate the field of heterogeneous catalysts.