Preparation of Catalyst ZIF-67 and Optimize on the Synthesis of D-Allulose

To reduce the manufacturing cost of D-allulose, a recyclable and reusable inorganic catalyst was developed for D-allulose production, and process using this catalyst to produce D-allulose also was optimized in this article. Zeolitic imidazolate framework-67 (ZIF-67) was synthesized using Co²⁺ and 2-methylimidazole in aqueous phase. Then the structure of ZIF-67 was characterized. The single factor test was carried out to select suitable value of pH (A), catalytic temperature (B) and reaction time (C). Based on the results of single factor experiments, the catalytic process was optimized using response surface methodology. The results showed that ZIF-67 had a rhombic dodecahedral structure and exhibited excellent catalytic performance. The Design Expert 13 software predicted the optimal reaction condition was pH11.1, 80.0 ℃ and 11.2 min. Under these conditions, the catalytic activity of ZIF-67 was 1003.5 µmol·min⁻¹·g⁻¹. A D-allulose inorganic catalyst was developed and the optimal reaction condition was carried out using response surface methodology in this paper. It also opens up a new path for the industrial production of D-allulose.