Identifying Key Features of Polyoxometalate Catalysts for the Anaerobic Conversion of Glucose Into Lactic Acid

The effective valorization of biomass to value‐added platform chemicals is one major aim of the green chemistry transition. A particularly promising compound in this context is lactic acid (LA), which is already extensively used in the chemical industry. This study investigates key features required for the homogeneously catalyzed transformation of glucose into LA by studying a library of polyoxometalate (POM) catalysts, with variations in structure, elemental composition, and countercation. The highest yield of LA (25 %) was obtained with the Keggin‐type vanadium‐substituted phosphotungstic acid H 6 PV 3 W 9 O 40 . Experimental and computational studies revealed that this performance correlates with high Brønsted and low Lewis acidity/fluoride ion affinity. Additionally, the catalyst exhibits a unique redox behavior as shown by square‐wave voltammetry. Further investigations of the reaction pathway revealed these characteristics affect mainly the retro‐aldol reaction of fructose to dihydroxyacetone, which was identified as the selectivity‐determining step. Overall, this study contributes to the transition to a green chemical industry by providing new insights into an efficient production of the sustainable platform chemical LA.