The effect of the layer-interlayer chemistry of LDHs on developing high temperature carbon capture materials†
The layer-interlayer chemistry of layered double hydroxides (LDHs) offers a vast opportunity to develop mixed metal oxides (MMOs) as novel sorbents for high temperature CO2 capture. Here, we report the synthesis of adamantanecarboxylate intercalated Ca–Al LDH by employing a co-hydration method. Thermal decomposition under a controlled atmosphere converts the layered metal hydroxides to MMOs and an intercalated anion into a carbonaceous support. The higher thermal stability and polymeric nature of the intercalated adamantanecarboxylate ion act as a thermal/mechanical support for the layered MMOs. The resultant hybrid solid sorbent shows excellent high temperature CO2 capture and cycling performance under both CO2 rich and lean (industrial flue gas) conditions. The hybrid sample shows almost 100% carbonation of all the active phase present, leading to maximum atom efficiency. The hybrid sorbent also shows rapid kinetics for both the carbonation and regeneration steps. The employed synthetic strategy offers a new approach to develop improved novel sorbents based on LDHs for high temperature CO2 capture.