A Prolific Catalyst for Selective Conversion of Neat Glycerol to Lactic Acid

Abstract

We report the synthesis and reactivity of a very robust iridium catalyst for glycerol to lactate conversion. The high reactivity and selectivity of this catalyst enable a sequence for the conversion of biodiesel waste stream to lactide monomers for the preparation of poly(lactic acid). Furthermore, experimental data collected with this system provide a general understanding of its reactive mechanism.

Hydrothermal conversion of high-concentrated glycerol to lactic acid catalyzed by bimetallic CuAux (x = 0.01–0.04) nanoparticles and their reaction kinetics

“…10-20% of raw material in weight. [1][2][3] Currently, in the United States, the biodiesel industry produces ca. 7.6 billion liters of glycerol each year, 1,4 which is oversupplied in the market.…”

“…[1][2][3] Currently, in the United States, the biodiesel industry produces ca. 7.6 billion liters of glycerol each year, 1,4 which is oversupplied in the market. Although the second-generation biofuels obtained from ligno-cellulose biomass and the third-generation biofuels produced from algae-derived biomass have been paid a great attention in Europe, 5 production of the rst-generation biofuels still steadily increases with the production amount of 9.9 billion liters in Europe because their production is cheaper than those of the second and third generation biofuels.…”

Glycerol to lactic acid conversion by NHC-stabilized iridium nanoparticles

“…surface-atom-related TOF value of 10 4 h À1 ) combined with the high selectivity for LA and easy recyclability (i.e. separation of the catalytic 1,4-dioxane solution from sodium lactate and excess GLY by simple decantation in air atmosphere) makes this catalytic system superior to the best known homogeneous catalysts of comparable LA selectivity [10,11].…”

“…obtained from biodiesel production [3]) give hydrogen as reaction product, obtained under acceptorless dehydrogenation reaction conditions [4][5][6][7][8]. Highly active Ru- [9] and Ir-based [10,11] molecular catalysts were employed to convert GLY to LA under acceptorless catalytic conditions, obtaining a LA selectivity of 96%. All successfully employed molecular Ir(I) catalysts are stabilized by N-heterocyclic carbene (NHC)-ligands, which are known to be suitable ligands for transition metals occurring in different oxidation states.…”

Efficient Generation of Lactic Acid from Glycerol over a Ru‐Zn‐CuI/Hydroxyapatite Catalyst

“…Lu et al. investigated the conversion of glycerol to LA by using homogenous iridium‐based catalytic systems under H 2 ‐acceptorless conditions, and a high yield of LA could be obtained . In heterogeneous catalytic systems, the conversion of glycerol to LA was investigated under reductive conditions or in the presence of a hydrogen acceptor.…”