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.