(205c) Preparation of Large-Pore-Volume Al2O3 Microspheres As Catalyst Support Via Microfluidics

Mesoporous alumina (Al₂O₃) is regarded as a potential candidate in catalysts, the textural properties of which affect the structure and performance of heterogeneous catalysts greatly. Herein, we report a systematic investigation of the preparation of large-pore-volume Al₂O₃ microspheres using microfluidics. The pore expansion mechanism of synthesis system with methylcellulose (MC) as the template and gelation initiator and an organic solvent as the swelling agent and carrier medium was investigated experimentally and theoretically. The coaxial microchannel was subjected to molding; this process significantly influenced the morphology and textural properties owing to the internal circulation during droplet formation, by which the obtained microspheres exhibited an optimal specific surface area of 403 m²/g and a pore volume of 1.85 cm³/g. To meet the demand for industrial application, a parallelized microfluidic device with improved ladder–tree distributors were developed for the scaled-up production of monodisperse microspheres with a CV of 2.58% in a production rate of 500 g/day. Finally, an optimized CO₂ conversion of 87.0% at 300 °C under atmospheric pressure was realized owing to the large pore volume and uniform Ni dispersion of Ni/Al₂O₃ microsphere catalysts. This work provides a feasible strategy of preparing Al₂O₃ microspheres with large pore volume as promising catalyst support, and have potential in the extensive industrial application for the preparation and molding of mesopore materials.