Advances in catalytic hydrogenolysis of glycerol to fine chemicals

Abstract

With the rapid growth of the biodiesel industry, huge amounts of glycerol have been produced as a byproduct. Thus, it is highly desirable to convert low-cost glycerol into highly valuable chemicals, which can both expedite the development of the biodiesel process and save abundant petroleum resources. In this context, one of the most promising approaches is the catalytic hydrogenolysis of glycerol to synthesize 1,2-propanediol (1,2-PDO), 1,3-propanediol (1,3-PDO), ethylene glycol (EG), and propanols, because these target products have higher selectivity, economic value and potential for industrial application. In this paper, glycerol chemistry will be briefly introduced and then the reaction mechanisms, including dehydration-hydrogenation, dehydrogenation-dehydration-hydrogenation, direct hydrogenolysis, and ionic hydrogenation, will be discussed because of their importance for understanding the catalytic chemistry. Subsequently, the catalytic applications of glycerol hydrogenolysis to obtain 1,2-PDO, 1,3-PDO, EG, and propanols will be reviewed in detail based on various catalysts. In the end, we will provide a short summary and an outlook on the future prospects for glycerol hydrogenolysis.