Ultrafast Carbon Dioxide Sorption Kinetics Using Lithium Silicate Nanowires

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Carbon dioxide (CO2) capture is crucial for mitigating climate change.
• Developing efficient sorbent materials with rapid kinetics is a key challenge.
• Lithium silicate (Li4SiO4) has shown potential for CO2 capture but requires kinetic enhancement.

Purpose of the Study:

• To synthesize and evaluate Li4SiO4 nanowires (NWs) for CO2 capture.
• To investigate the adsorption kinetics and capacity of Li4SiO4 NWs.
• To compare the performance of Li4SiO4 NWs with other morphologies.

Main Methods:

• Synthesis of Li4SiO4 nanowires and nanopowders using a "solvo-plasma" technique.
• Characterization of material morphology and composition.
• Measurement of CO2 sorption kinetics and capacity at elevated temperatures (650-700 °C).

Main Results:

• Li4SiO4 NWs exhibited ultrafast CO2 adsorption kinetics.
• An uptake of 0.35 g g⁻¹ of CO2 was achieved at an adsorption rate of 0.22 g g⁻¹ min⁻¹.
• Kinetic parameters were 1 order of magnitude higher than previously reported Li4SiO4 materials, with sorption times ~3 min.

Conclusions:

• Li4SiO4 nanowires are highly promising for CO2 capture due to their superior adsorption kinetics.
• The materials demonstrated reversibility over sorption-desorption cycles, indicating practical applicability.
• The observed double exponential adsorption behavior suggests distinct kinetic and mass transfer regimes.