Study The Schiff Base Catalytic Activity In The Oxidation Of Glucose

Gluconic acid and its derivatives are important organic chemicals, which can be extensively used in the chemical industry, light industry, medicine, food etc. Its demand is also increasing fast. The most interesting field of producing gluconic acid are the heterogeneous catalytic oxidation of glucose. The noble metal catalyst such as Pt, Pd, and Au etc. was used in this method currently. Considering the expensive cost of production, the industry application of the noble metal catalyst is restricted. In order to overcome these weaknesses, the activity of non-precious metal and free-metal catalysts in gluconic acid production by oxidative reaction is investigated in this thesis.Firstly, the catalyst activity of CuCl/phen, CoCl₂/phen, FeSO₄/phen, NiCl₂/phen etc. in the glucose oxidative reaction has been studied. The results show that CuCl/phen catalyst presents the best catalytic performance. Under the reaction conditions of bubbling(3.5L/min) and stirring(600r/min) for 4h, 50℃, pH=10.0, the concentration of glucose 947mmol/L, and catalyst 1.5mmol/L, the conversion of glucose was 20%, the selectivity of gluconic acid was 57%.Secondly, the catalyst performance of nonmetal organic compound containing nitrogen, such as 1, 10-phenanthroline, N-methylimidazole, L-proline etc. has been also investigated. The results showed that 1, 10-phenanthroline had high activity in the oxidative reaction. Under the reaction conditions of bubbling(3.5L/min) and stirring (600r/min) for 8h, 50℃, pH=9.5, the concentration of glucose 947mmol/L, and catalyst 1.0mmol/L, N-methylimidazole (NMI) promoter 1.0mmol/L, the conversion of glucose reached 21%, in which the selectivity of gluconic acid was 70%.