Formation of Formic Acid from Glucose with Simultaneous Conversion of Ag₂O to Ag under Mild Hydrothermal Conditions

Abstract

Formation of formic acid from renewable biomass resources is of great interest since formic acid is a widely used platform chemical and has recently been regarded as an important liquid hydrogen carrier. Herein, a novel approach is reported for the conversion of glucose, the constituent carbohydrate from the cellulose fraction of biomass, to formic acid under mild hydrothermal conditions with simultaneous reduction of Ag 2 O to Ag. Results showed that glucose was selectively converted to formic acid with an optimum yield of 40.7% and glycolic acid with a yield of 6.1% with 53.2% glucose converting to carbon dioxide (CO 2 ) immediately at a mild reaction temperature of 135 °C for 30 min. In addition, Ag 2 O was used as a solid oxidant for glucose oxidation, which avoids the use of traditionally dangerous liquid oxidant H 2 O 2 . Furthermore, complete conversion of Ag 2 O to Ag can be achieved. This study not only developed a new method for value-added chemical production from renewable biomass but also explored an alternative low-carbon and energy-saving route for silver extraction and recovery.

Reaction pathways and kinetics of N-acetyl-d-glucosamine hydrolysis in sub- and supercritical water

“…It is suggested that FA forms mainly by C-C cleavage of glucose, as reported earlier, and by oxidation of glucose. 32 The formation of DP from both reactions showed non-Arrhenius behaviour. As the lumped terms 'I' and 'DP' take into account the combined unknown reactions occurring during NAG hydrolysis, deviation from ideal Arrhenius behaviour also suggests that a few of these reactions could be reversible.…”

“…The only pathway to form glycolic acid and formic acid is by oxidation of glucose, which was also previously reported to happen at the hydrothermal liquefaction of cellulose. 32,33 Hence, the reaction medium favours both oxidation and reduction. Another important compound 5-HMF was believed to be formed by the dehydration of glucose.…”

Glucaric Acid Production from Miscanthus sacchariflorus via TEMPO-Mediated Oxidation with an Efficient Separation System

“…Meanwhile, formic and oxalic acid contents in model compounds showed results similar to those in the absence of impurities. It was assumed that xylose-and ligninderived phenolic compounds could be converted to formic acid or oxalic acid via the oxidative C−C cleavage of xylose 29 and oxidative ring-opening of lignin. 48 Therefore, formic acid and oxalic acid were produced sufficiently due to the oxidation of xylose and lignin, even though glucose was not oxidized sufficiently.…”

Molybdenum sulfide-2D nanosheets offering multiple metallic sites enable different sugar epimerization reactions to rare sugars in water

“…This less effect on HMF formation can possibly be due to the non-availability of the Brønsted acid sites favorable for fructose dehydration 41 and the non-generation of sugar acids that can influence this extended side reaction. 42 Perhaps the catalyst prompted the synthesis of a higher number of non-detectable sugar derivatives, including humin, 43 resulting in an abnormal ratio of glucose conversion to mannose yield (i.e., up to 2 times lower). The temperature was also not favorable for activating any unwanted product synthesis (≤120 °C), like HMF.…”