Biomass oxidation to formic acid in aqueous media using polyoxometalate catalysts - boosting FA selectivity by in-situ extractionElectronic supplementary information (ESI) available: Tables for extraction solvent screening, NMR spectra of the esterification tests, NMR spectra of 1-hexanol, 1-heptanol stability tests, GC-MS analysis of products from 13C glucose oxidation, FA product stability in the reaction phase, ester formation between toluenesulfonic acid and the alcoholic extraction solvent.

• Main Authors: Reichert, Jenny, Brunner, Birgit, Jess, Andreas, Wasserscheid, Peter, Albert, Jakob
• Format: Journal Article
• Language: English
• Published: 02.10.2015
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c5ee01706h

Herein, we report a remarkable finding that biomass oxidation to formic acid (FA) in water-organic biphasic reaction systems is far more selective than the same reaction in a monophasic aqueous media. While literature claims that the yield of FA from carbohydrates and biomass is limited to less than 68%, even for simple substrates such as glucose or glycerol, we demonstrate in this study that FA yields of up to 85% can be obtained from glucose. Using our biphasic reaction protocol, even raw lignocellulosic biomass, such as beech wood, leads to FA yields of 61%. This is realized by applying polyoxometalate H 8 PV 5 Mo 7 O 40 as a homogeneous catalyst, oxygen as the oxidant and water as the solvent in the presence of a long-chain primary alcohol as an in-situ extracting agent. The new, liquid-liquid biphasic operation opens a highly effective way to produce pure FA, a liquid syngas equivalent, from wood in a robust, integrated, and low-temperature process. 1-Hexanol and 1-heptanol were applied as in-situ extracting agents in the oxidation reaction of biomass to formic acid (FA) using a Keggin-type polyoxometalate (H8PV5Mo7O40) as a homogeneous catalyst, oxygen as the oxidant and water as the solvent.