TY - JOUR
T1 - Conversion of Sugars to Lactic Acid using Homogeneous Niobium-Substituted Polyoxometalate Catalysts
AU - Wesner, Anne
AU - Raabe, Jan Christian
AU - Poller, Maximilian J.
AU - Meier, Sebastian
AU - Riisager, Anders
AU - Albert, Jakob
N1 - Publisher Copyright:
© 2024 The Author(s). Chemistry - A European Journal published by Wiley-VCH GmbH.
PY - 2024
Y1 - 2024
N2 - The catalytic conversion of biomass into high-value chemicals is an increasing field of research. This study uniquely investigates the use of various Keggin-type heteropoly salts (HPS) for the chemical conversion of sugars into lactic acid under mild conditions of 160 °C and 20 bar N2. In the first phase, Nb– and V–substituted HPSs were employed to synthesize lactic acid from dihydroxyacetone, an intermediate in the conversion of sugars to lactic acid. Results indicated that increasing the Nb content within the Keggin structure enhances the yield of lactic acid while reducing the formation of the byproduct acetaldehyde. A correlation was established between the redox activity of the HPS and the catalytic performance. The most active catalyst, Na5[PNb2Mo10O40], (NaNb2) achieved a lactic acid yield of 20.9 % after 1 h of reaction. In the second phase of the study, NaNb2 was applied for the conversion of different sugars including glucose, fructose, mannose, sucrose, xylose, and cellobiose. It was demonstrated that the catalyst remains active for complex hexoses, achieving lactic acid yields of up to 12 %. Post-mortem analysis using infrared (IR) and Raman spectroscopy, nuclear magnetic resonance (NMR), and inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed the stability of NaNb2.
AB - The catalytic conversion of biomass into high-value chemicals is an increasing field of research. This study uniquely investigates the use of various Keggin-type heteropoly salts (HPS) for the chemical conversion of sugars into lactic acid under mild conditions of 160 °C and 20 bar N2. In the first phase, Nb– and V–substituted HPSs were employed to synthesize lactic acid from dihydroxyacetone, an intermediate in the conversion of sugars to lactic acid. Results indicated that increasing the Nb content within the Keggin structure enhances the yield of lactic acid while reducing the formation of the byproduct acetaldehyde. A correlation was established between the redox activity of the HPS and the catalytic performance. The most active catalyst, Na5[PNb2Mo10O40], (NaNb2) achieved a lactic acid yield of 20.9 % after 1 h of reaction. In the second phase of the study, NaNb2 was applied for the conversion of different sugars including glucose, fructose, mannose, sucrose, xylose, and cellobiose. It was demonstrated that the catalyst remains active for complex hexoses, achieving lactic acid yields of up to 12 %. Post-mortem analysis using infrared (IR) and Raman spectroscopy, nuclear magnetic resonance (NMR), and inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed the stability of NaNb2.
KW - Biomass conversion
KW - Lactic acid
KW - Niobium-substituted heteropoly salts
KW - Polyoxometalates
U2 - 10.1002/chem.202402649
DO - 10.1002/chem.202402649
M3 - Journal article
C2 - 39315518
AN - SCOPUS:85207938944
SN - 0947-6539
VL - 30
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 69
M1 - e20240264
ER -