Shape‐selective Valorization of Biomass‐derived Glycolaldehyde using Tin‐containing Zeolites

Abstract

A highly selective self-condensation of glycolaldehyde to different C molecules has been achieved using Lewis acidic stannosilicate catalysts in water at moderate temperatures (40-100 °C). The medium-sized zeolite pores (10-membered ring framework) in Sn-MFI facilitate the formation of tetrose sugars while hindering consecutive aldol reactions leading to hexose sugars. High yields of tetrose sugars (74 %) with minor amounts of vinyl glycolic acid (VGA), an α-hydroxyacid, are obtained using Sn-MFI with selectivities towards C products reaching 97 %. Tin catalysts having large pores or no pore structure (Sn-Beta, Sn-MCM-41, Sn-SBA-15, tin chloride) led to lower selectivities for C sugars due to formation of hexose sugars. In the case of Sn-Beta, VGA is the main product (30 %), illustrating differences in selectivity of the Sn sites in the different frameworks. Under optimized conditions, GA can undergo further conversion, leading to yields of up to 44 % of VGA using Sn-MFI in water. The use of Sn-MFI offers multiple possibilities for valorization of biomass-derived GA in water under mild conditions selectively producing C molecules.

Quantitative NMR Approach to Optimize the Formation of Chemical Building Blocks from Abundant Carbohydrates

“…The use of NMR spectroscopy for component identification and quantification is particularly well-developed for biological samples,i ncluding biofluids, extracts,a nd foods, buth as also gainedp opularity within biomass conversion,f or instancei nt he study of carbohydrate isomerization reactions [15][16][17] or for lignin structure and depolymerization reactions. The use of NMR spectroscopy for component identification and quantification is particularly well-developed for biological samples,i ncluding biofluids, extracts,a nd foods, buth as also gainedp opularity within biomass conversion,f or instancei nt he study of carbohydrate isomerization reactions [15][16][17] or for lignin structure and depolymerization reactions.…”

“…[17] In the current analysiso fs olvent effects, the use of less nucleophilic and more bulky solvents increases the selectivity towardt he formation of C5 lactones (compound 6). [17] In the current analysiso fs olvent effects, the use of less nucleophilic and more bulky solvents increases the selectivity towardt he formation of C5 lactones (compound 6).…”

Thermal Cracking of Sugars for the Production of Glycolaldehyde and Other Small Oxygenates

“…[11] For achemical industry based on renewable feedstocks, new platform molecules will be needed. [12] Glycolaldehyde (hydroxyacetaldehyde) may be one such platform molecule for ab iomass-based chemical industry.G lycolaldehyde can be transformed into other useful chemicals, such as ethyl-ene glycol by catalytic hydrogenation, [13] glycolic acid by mild oxidation, [14] methyl vinyl glycolate (MVG), [15][16][17] and ethanol amines [18][19][20] (Scheme 1).…”

Copper Supported on Hybrid C@SiO2 Hollow Submicron Spheres as Active Ethanol Dehydrogenation Catalyst

“…During the dehydrogenation of ethanol on Cu/SiO 2 catalyst, the acetaldehyde, a primary product, can undergo secondary reactions leading to numerous byproducts (e. g., ethyl acetate and butyraldehyde) by Si‐OH of the support surface or undesired Cu δ+ sites ,. For comparison, acetaldehyde yield for catalysts with different supports were investigated as a function of conversion (Figure b).…”

“…During the dehydrogenation of ethanol on Cu/SiO 2 catalyst, the acetaldehyde, a primary product, can undergo secondary reactions leading to numerous byproducts (e. g., ethyl acetate and butyraldehyde) by Si-OH of the support surface or undesired Cu d + sites. [15,26] For comparison, acetaldehyde yield for catalysts with different supports were investigated as a function of conversion (Figure 4b). Clearly, the hybrid C@SiO 2 supported Cu catalysts show an excellent acetaldehyde selectivity which is similar to Cu/Carbon catalyst, but higher than Cu/SiO 2 catalyst in the test range.…”