Lead Looping for Low-Temperature CO₂ Capture and Release

Abstract

The sustainable use of metal oxides to rapidly capture and release CO2 as a C1 building block at a low energy cost is appealing yet challenging. Herein, we show that vicinal diols (e.g., ethylene glycol, glycerol, and 1,2-propanediol) can significantly accelerate the carbonation rates of PbO at ambient conditions, accompanied by a CO2 uptake capacity (567 mmol mol–1) comparable to that of the frequently used CaO and MgO. It is revealed that the in situ generated metal–organic hybrid materials of PbO and vicinal diols are the key intermediates for the reaction cycle. They can rapidly react with CO2 to generate PbCO3, accompanied by the release of vicinal diols for the next reaction cycle. The accelerated CO2 capture at ambient conditions coupled with the easy regeneration of PbO and release of CO2 via calcination of PbCO3 at a low temperature (∼300 °C) constitutes a new lead looping process with low energy input.