Ultrafast Carbon Dioxide Sorption Kinetics Using Lithium Silicate Nanowires.

In this paper, the LiSiO nanowires (NWs) were shown to be promising for CO capture with ultrafast kinetics. Specifically, the nanowire powders exhibited an uptake of 0.35 g g of CO at an ultrafast adsorption rate of 0.22 g g min at 650-700 °C. Lithium silicate (LiSiO) nanowires and nanopowders were synthesized using a "solvo-plasma" technique involving plasma oxidation of silicon precursors mixed with lithium hydroxide. The kinetic parameter values (k) extracted from sorption kinetics obtained using NW powders are 1 order of magnitude higher than those previously reported for the LiSiO-CO reaction system. The time scales for CO sorption using nanowires are approximately 3 min and two orders magnitude faster compared to those obtained using lithium silicate powders with spherical morphologies and aggregates. Furthermore, LiSiO nanowire powders showed reversibility through sorption-desorption cycles indicating their suitability for CO capture applications. All of the morphologies of LiSiO powders exhibited a double exponential behavior in the adsorption kinetics indicating two distinct time constants for kinetic and the mass transfer limited regimes.