Lactic acid and hydrogen from glycerol via acceptorless dehydrogenation using homogeneous catalysts

Acceptorless dehydrogenation of alcohols has emerged as a powerful methodology for the valorization of biomass derived platform chemicals and building blocks. In this review we provide a short overview of the advantages
and possible product outcomes of this method. The main focus will be devoted to the conversion of glycerol, which is the major waste product of biodiesel production, to lactic acid. While extensive research addresses the development
of heterogeneous catalysts, recently new and highly active iridium and ruthenium complexes have also been reported.These novel homogeneous catalysts are even more active than the already reported heterogeneous systems and enable the direct conversion of glycerol into lactic acid and molecular hydrogen. While the product hydrogen might be used either as fuel or as reducing agent for other processes, lactic acid is a platform chemical widely employed by the polymer, pharmaceutical and food industries. The used
catalytic methodology is atom-economic, waste-free and is uniquely suited for the efficient conversion of renewable resources.