Saccharide formation by sustainable formose reaction using heterogeneous zeolite catalysts

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 53; no. 6; pp. 2678 - 2686
• Main Authors: Waki, Minoru, Shirai, Soichi, Hase, Yoko
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 06.02.2024
• Subjects: Aluminosilicates; Aluminum oxide; Aluminum silicates; Aqueous solutions; Basicity; Calcium ions; Carbohydrates; Carbon compounds; Catalysts; Catalytic activity; Chemical reactions; Covalent bonds; Formaldehyde; High performance liquid chromatography; Hydroxyapatite; Infrared analysis; Metal ions; NMR; Nuclear magnetic resonance; Oxygen atoms; Pentose; Reaction mechanisms; Room temperature; Silicon dioxide; Zeolites
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d3dt02321d

The formose reaction is a unique chemical reaction for the preparation of saccharides from formaldehyde, a single carbon compound. We applied zeolite materials as heterogeneous catalysts to the formose reaction. The simple addition of Linde type A zeolite containing calcium ions (Ca-LTA) to an aqueous solution of formaldehyde and glycolaldehyde produced saccharides at room temperature. A quantitative analysis performed by high-performance liquid chromatography revealed that triose, tetrose, pentose, and hexose saccharides were produced with few byproducts. Ca-LTA was recovered from the reaction mixture by filtration, and the retrieved zeolite was found to be reusable under the same conditions. The catalytic activity of Ca-LTA was higher than those of conventional calcium catalysts and other solid materials such as silica, alumina, and hydroxyapatite. Several other types of zeolites with different crystal structures and alkali/alkali-earth metal ions also showed catalytic activity for saccharide formation. Based on the analytical results obtained by infrared spectroscopy, temperature-programmed desorption profiles and NMR measurements, we propose a reaction mechanism in which C-C bond formation is promoted by the mild basicity of the oxygen atoms and acidity on the metal ions of the aluminosilicate on the zeolite surfaces with low SiO 2 /Al 2 O 3 ratios. Linde type A zeolite catalyzes saccharide formation of formaldehyde and glycolaldehyde in a heterogeneous formose reaction in aqueous solution.