Low-Temperature and Fast Kinetics for CO₂ Sorption Using Li₆WO₆ Nanowires.

Abstract

In this paper, lithium hexaoxotungstate (Li₆WO₆) nanowires were synthesized via facile solid-state reaction and were tested for CO₂ capture applications at both low (<100 °C) and high temperatures (>700 °C). Under dry conditions, the nanowire materials were able to capture CO₂ with a weight increment of 12% in only 60 s at an operating temperature of 710 °C. By contrast, under humidified ambience, Li₆WO₆ nanowires capture CO₂ with weight increment of 7.6% at temperatures as low as 30-40 °C within a time-scale of 1 min. It was observed that the CO₂ chemisorption in Li₆WO₆ is favored in the oxygen ambience at higher temperatures and in the presence of water vapor at lower temperatures. Nanowire morphology favors the swift lithium supply to the surface of lithium-rich Li₆WO₆, thereby enhancing the reaction kinetics and lowering time scales for high capacity adsorption. Overall, high chemisorption capacities, superfast reaction kinetics, wide range of operating temperatures, and reasonably good recyclability make 1-D Li₆WO₆ materials highly suitable for various CO₂ capture applications.