Recent Developments of Heterogeneous Catalysts for Hydrogenation of Carboxylic Acids to their Corresponding Alcohols

Hydrogenation of carboxylic acids is an important organic reaction for the synthesis of alcohols, aldehydes, alkanes, and so on. Selective hydrogenation of carboxylic acids to alcohols is particularly important because alcohols are useful and valuable chemicals. However, the hydrogenation of carboxylic acids is difficult due to the low reactivity of the carboxy group and the acidic property, which require rational design of catalysts. Up to now, various effective homogeneous and heterogeneous catalysts have been intensively developed, and remarkable advances have been made in heterogeneous catalysts. In this minireview, recent progress (2010 and after) on the development of heterogeneous catalysts for hydrogenation of carboxylic acids to alcohols, particularly for monocarboxylic acids to mono primary alcohols, is reviewed. The reported literatures were categorized in terms of catalyst systems, such as monometallic catalysts and bimetallic catalysts. The characteristics, particularly the structure of active sites, reaction mechanism and stability, were introduced.