Confined Jet Impingement Continuous Microchannel Reactor Synthesis of Ultrahigh-Quality Mesoporous Silica Nanospheres for CO₂ Capture

Li4SiO4 has been evaluated as one of the most promising CO2 absorbers to mitigate climate changes caused by excessive CO2 emissions. Li4SiO4 absorbents with a high specific surface area would hold higher CO2 capture capacity. However, with the lack of suitable SiO2 precursors, the synthesis of Li4SiO4 absorbents with a high specific surface area and a well-defined hollow sphere structure was still challenging. Here, a two-stream confined jet impingement continuous microchannel reactor was proposed to produce ultrahigh-quality mesoporous silica nanospheres (UHMSNs) with an ultrahigh specific surface area and a small particle size. The obtained UHMSNs possessed excellent water dispersibility, a uniform diameter (142-207 nm), tunable perpendicular mesopores (2.6-3.3 nm), a high surface area (1347 similar to 1854 m(2)/g), and a large pore volume 0.86 similar to 1.23 cm(3)/g). Moreover, MesoDyn simulation provided valuable information to optimize the nucleation stage and the crystallization stage of UHMSNs. Additionally, UHMSNs were used as the silicon source to synthesize the petal-like hollow structure of Li4SiO4 microspheres, which enhanced CO2 adsorption.