Adjusting the GeO2 catalyst crystal system to enhance the efficiency of polyester catalysis

Enhancing the catalytic activity of germanium-based catalysts can reduce their required dosage and effectively lower the production cost of high-end polyester. Numerous studies have demonstrated that variations in catalyst crystal structures exert a decisive influence on their activity, selectivity, and stability. Based on this observation, the adsorption energy of tetragonal germanium dioxide (GeO 2 ) on polyester reactants was calculated through molecular simulations, revealing that tetragonal GeO 2 possesses a stronger adsorption capacity for polyester reactants than hexagonal GeO 2 . Subsequently, a novel low-temperature hydrothermal approach was developed to synthesize small-sized tetragonal GeO 2 . This approach reduces the crystal transition temperature from 1000 °C to 240 °C, thereby significantly lowering the energy consumption of the process. The catalytic activities of GeO 2 with different crystal systems were analyzed using kinetic studies. Polyethylene terephthalate (PET) samples synthesized from GeO 2 catalysts with different crystal systems were subsequently characterized. The results indicate that tetragonal GeO 2 exhibits superior catalytic activity, and the resulting PET polyester displays improved color, transparency, and thermal stability. These findings confirm the feasibility of enhancing the catalytic performance of germanium-based catalyst systems through crystal transformation. This work provides new insights and possibilities for the future development of high-performance polyester products and efficient germanium-based polyester catalysts.