Kinetic study of retro‐aldol condensation of glucose to glycolaldehyde with ammonium metatungstate as the catalyst

The kinetics of the retro‐aldol condensation of glucose to glycolaldehyde was studied in a batch reactor at 423–453 K using ammonium metatungstate (AMT) as the catalyst. Three consecutive reactions were considered: retro‐aldol condensation of glucose to erythrose and glycolaldehyde (R1), retro‐aldol condensation of erythrose to two moles of glycolaldehyde (R2), and further conversion of glycolaldehyde to side products (R3). Fitting of the experimental data showed that R1 was first‐order reaction while R2 and R3 were 1.7th‐ and 2.5th‐order reaction, respectively. Conversely, the reaction rate of R1 was 0.257th‐order dependence on the concentration of AMT catalyst. The apparent activation energies for R1, R2, and R3 were 141.3, 79.9, and 52.7 kJ/mol, respectively. The high activation energy of R1 suggests that a high temperature is favorable to the formation of glycolaldehyde. The experimental C–t curves at different temperatures and initial glucose concentrations were well predicted by the kinetic model.